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United States Department of Agriculture Forest Service

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Myotis sodalis), including its selection of and use of hibernacula, roost trees, and foraging habitat. An extensive list of published references related to the Indiana bat is included. The Authors MICHAEL A. MENZEL and JOHN W. EDWARDS are wildlife biologists with West Virginia University's Division of Forestry at Morgantown. JENNIFER M. MENZEL and W. MARK FORD are research wildlife biologists with the Northeastern Research Station in Parsons. TIMOTHY C. CARTER is a wildlife biologist with Southern Illinois University's Department of Zoology at Carbondale. Manuscript received for publication 24 May 2001 Contents
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UNITED STATES
DEPARTMENT OF AGRICULTURE
FOREST SERVICE
FATAL AVIATION
ACCIDENT HISTORY
Compiled By: Candy S. Rock FitzPatrick
1
TABLE OF CONTENTS
Section One – Fatal Airtanker Mishaps
Aircraft
Pages
Date
Region
Boeing B-17G (B-17) 8-10
July 21, 1979
Northern Region
Douglas Commercial DC-4 11-12
Mid-air Collision
December 2, 1980
Pacific Southwest Region
Fairchild C-119 13-14
July 8, 1981
Pacific Southwest Region
Douglas B-26 15-16
March 5, 1983
Southern Region
Fairchild C-119G (3E) 17-18
September 16, 1987
Pacific Southwest Region
Lockheed P2V-7 19-20
September 30, 1990
Pacific Northwest Region
Lockheed P-3A Orion 21-23
October 16, 1991
Northern Region
Douglas Commercial DC-7B 24-25
October 1, 1992
Pacific Southwest Region
Lockheed P2V-7 Neptune 26-28
July 29, 1994
Northern Region
2
Lockheed C-130A 29-31
August 13, 1994
Pacific Northwest Region
Beechcraft Model 58P Baron 32-34
Douglas C-54G
Mid-air Collision
June 21, 1995
Pacific Southwest Region
Lockheed P2V-7 Neptune 35-36
June 27, 1998
Southwest Region
Lockheed C-130A 37-38
June 17, 2002
Pacific Southwest Region
Consolidated Vultee 39-41
PB4Y-2 Privateer
July 18, 2002
Rocky Mountain Region
Section Two – Fatal Helicopter Mishaps
Bell 47-G3B-1 43-44
July 17, 1976
Alaska Region
Bell 205A-1 45-48
Bell 212
Mid-air Collision
July 24, 1977
Pacific Southwest Region
Hiller Model 12J3 49-50
July 28, 1977
Alaska Region
Bell 206BIII 51-53
August 22, 1984
Intermountain Region
3
Aerospatiale Alouette III 54-55
(SA316B)
August 9, 1985
Pacific Northwest Region
Bell 206BII Jet Ranger 56-59
March 6, 1987
Alaska Region
UH-1B 60-63
June 14, 1988
Pacific Northwest Region
Aerospatiale SA315B Lama 64-66
August 19, 1988
Rocky Mountain Region
Bell 206LI 67-68
July 26, 1991
Pacific Southwest Region
Bell 206LIII 69-71
July 12, 1994
Southwest Region
Boeing Vertol CH-47D 72-73
Chinook
September 23, 1994
Intermountain Region
Bell 47 Soloy 74-75
October 29, 1996
Intermountain Region
Bell 206LI 76-78
July 6, 1997
Pacific Southwest Region
OH-58A Kiowa 79-81
June 24, 1998
Southern Region
Aerospatiale AS315B Lama 82
July 30, 2002
Rocky Mountain Region
4
Section Three – Other Fatal Mishaps
DeHavilland DHC-II Beaver 84
October 17, 1974
Alaska Region
Douglas Commercial DC-3 85-88
C-47
June 11, 1979
Intermountain Region
Aero Commander 500B 89-90
August 4, 1980
Intermountain Region
Beechcraft Model 58P Baron 91-92
May 11, 1981
Pacific Southwest Region
Cessna T210 93-94
September 9, 1983
Rocky Mountain Region
Cessna T337G 95-97
July 23, 1984
Southwest Region
DeHavilland DHC-6 300 98-99
Twin Otter
July 14, 1988
Pacific Southwest Region
Beechcraft 200 King Air 100-101
September 11, 1988
Pacific Southwest Region
Beechcraft Model 58P Baron 102-103
August 12, 1988
Pacific Southwest Region
Beechcraft Model 58P Baron 104-105
June 21, 1991
Southwest Region
5
Beechcraft Model 58P Baron 106-109
November 2, 1992
Pacific Northwest Region
Cessna T337C 110-112
May 15, 2000
Southwest Region
6
LEARNING
EXPERIENCES
Section One
FATAL
AIRTANKER
MISHAPS
7
The afternoon of July 21, 1979 found this contract airtanker, a Boeing B-17G (B-17), and her two-person
flight crew dropping retardant on fires in the Two Creek Drainage Basin of the Superior Ranger District,
Montana. The Superior Ranger District is part of the West Zone Dispatch Office area located in St. Regis,
Montana.
Their initial dispatch to this fire occurred at 1411 hours Mountain Daylight Time (MDT). They proceeded
to make one flight consisting of four retardant drops. A United States Department of Agriculture Forest
Service leadplane pilot supervised the airtanker while it made two of those successful drops on the fire.
The leadplane was released and returned to the Missoula Aerial Fire Depot at 1545 MDT.
At 1604 MDT, the B-17 airtanker was dispatched to a different fire on the Lolo National Forest. A
leadplane was not available on this second fire to provide supervision. A leadplane was not required since
this airtanker Captain was a certified Initial Attack Pilot and as such, was authorized to make retardant
drops without supervision of a leadplane.
The first series of drops by the airtanker on this second fire were commenced at about 1625 MDT. They
completed four drops without the assistance of a leadplane. Several individuals, including the pilot of a
Twin Otter on a smokejumper mission, observed these drops.
The airtanker returned to the airtanker base (ATB) at 1655 MDT. The airtanker was re-loaded with 1,800
gallons of retardant, serviced with 380 gallons of fuel, and filled with 15 to 17 gallons of oil in preparation
for another run on the fire. This airtanker was dispatched a second time to that same fire at 1739 MDT.
Their departure time from the airport was recorded as 1748 MDT. Their flight from the airport back to the
fire took about 15 minutes.
Upon returning to the fire, the airtanker made a high pass over the fire and then an approach for a second
pass. The fire was located near the top of a mountainous ridge on an even slope that provided an easy
target for a retardant drop. Once the pass had been made, no retardant had been dropped. Immediately
after the airtanker passed over the drop target, it made a steep left turn and impacted a densely timbered
hillside.
Many people witnessed this final flight path ending when the airtanker impacted terrain at 1810 MDT.
Search and rescue efforts located the mishap site quickly and within 20 minutes, smokejumpers, including
an Emergency Medical Technician (EMT), arrived on scene. The Captain and Copilot were killed upon
impact.
The mishap site was located approximately ten miles southwest of Superior, Montana and 45 miles west of
Missoula, Montana.
Many of the witnesses who observed this airtanker’s flight patterns on this series of drops unanimously
agreed they were unorthodox and dangerous. The airtanker had narrowly missed a spur ridge following a
left turn up a gulch after its first retardant run. The safe, recommended flight pattern on this fire over this
terrain, later selected by a leadplane and used several times by another airtanker, was down drainage to the
north until sufficient altitude could be gained, then a right turn, back track pattern back to the fire area. The
mishap airtanker’s drops were on target and effective, in spite of their varying patterns.
Witnesses did not observe retardant being dropped during the final pass over the drop zone, although one
person stated that a pink cloud of what was believed to be retardant was observed dropping from the
airtanker about one quarter of a mile before the impact point. No physical evidence of retardant stains on
trees or the ground supporting this sighting could be located during an air search. There was no indication
that the retardant load had been deliberately jettisoned by the pilots when they recognized the hazardous
situation they had flown into.
Terrain features were very steep and tree covered throughout the area. Tree heights were estimated to
average 80 feet.
8
The airtanker made initial contact with the trees about 150 yards before impacting the ground. The final
approach heading was about 130 degrees. Witness marks on the trees indicated the descent angle was 20
degrees at an extremely steep left bank of 60 to 65 degrees. Ground impact occurred on the west side of
the drainage at the 5,200-foot level on a 40-degree slope.
Ground impact occurred in an estimated 5 to 10 degree nose low attitude and approximately a 40-degree
left bank. On site wreckage examination revealed the flaps were set at about 15 degrees. There was no
indication that any of the four engines had been feathered as all appeared to have been under power upon
impact. The steep left bank was beginning to shallow; this can probably be attributed to the tree strikes and
the B-17’s aileron reversal tendency during stalls.
The general weather in the fire area included good visibility and temperatures in the high 80 degrees
Fahrenheit with scattered clouds and light wind. The sun angle and terrain shadows should not have
presented a hazard for the crew.
The investigation team determined that during the sequence of events, the airtanker’s flight path during the
left turn was taking it too close to the mountainside. This required more bank angle and gravity forces to
increase the rate of turn and hold altitude in order to clear the mountainside. Unfortunately, as bank angles
and load factors increased, induced drag, which predominates at low speeds, also increased dramatically.
These factors would have required significant increases in power to maintain flight and preclude stalling.
The airtanker’s situation, already critical because of its low airspeed, low altitude, and the turning space
restriction, was compounded by the additional bank angle and increased load factor. The fringe of a stall
was entered and aggravated by the addition of aileron and elevator input to increase the rate of turn. Power
was insufficient to maintain flight and a few seconds later the airtanker completely stalled when
performance demands could not be maintained. Close proximity to the ground precluded the use of normal
stall recovery techniques, and the airtanker descended into the trees.
The Captain and Copilot were both qualified and approved for the mission. The Captain had flown this
airtanker 88.6 hours since April 6, 1979 and the Copilot had been his copilot for 83.9 of those hours since
May 23, 1979. The Captain and Copilot successfully flew retardant drop assignments in this airtanker in a
variety of fire conditions and terrain in three different regions since April 6, 1979. During this contract
season, either a leadplane or an air attack aircraft on 84 percent of their missions, had supervised this crew.
The investigation team determined that the Captain occupied the left seat and the Copilot occupied the right
seat at the time of the mishap.
The Captain had accumulated 2,089 hours of total flight time as the Pilot in Command (PIC), including 699
hours in multi-engine aircraft. He had 649 hours in the B-17 and 539 hours low-level flight time (under
500 feet) as of July 21, 1979.
The Copilot’s experience consisted of 899.6 PIC hours with 109 hours in multi-engine aircraft. He had
85.3 hours in the B-17 and 86 hours low-level flight time as of July 21, 1979.
The day of the mishap was both pilots’ first day back on the job after one day off spent on the ground.
Analysis of pathology reports tended to support the theory that the Copilot was flying the aircraft at the
time of impact. However, no conclusive evidence suggested which pilot initiated the fatal left turn.
Toxicology reports indicated alcohol in the Copilot’s stomach (.085 percent) and blood (.072 percent), but
not in his urine. The medical examiner estimated that this alcohol level could have been caused by the
consumption of two to four beers within 45 minutes prior to the mishap.
9
Boeing B-17G (B-17) wreckage location.
10
December 2, 1980 was a clear day. Airtankers “T1” and “T2,” both Douglas Commercial (DC) DC-4’s,
departed the Hemet-Ryan Airport in California at 1322 hours Pacific Standard Time (PST) and 1323 PST
respectively. Both airtankers had been recently released by the Forest Service from southern California fire
assignments and were headed for their home base in Tucson, Arizona. No flight plan had been filed with
the Federal Aviation Administration (FAA), although the crews intended to file one in flight.
While enroute, the crew of T1 engaged in taking in-flight photographs of T2 at an altitude of approximately
9,500 feet. T1 was flying in formation with T2 at his four to five o’clock position. The pilot of T1 stated
over the radio that they were going to cross over to the other side of T2 to take more photographs. T2 gave
permission and said that he would hold steady. The repositioning path T1 flew was a 45 degree overtaking
angle from the four to five o’clock position toward the 10 to 11 o’clock position of T2. The vertical
separation between the two airtankers was insufficient and a mid-air collision occurred.
The vertical fin of T1 struck the right wing flap of T2. T1’s fin and rudder were sheared off by that impact.
The retardant tanks of T2 compressed the top aft end of the fuselage of T1. The number two propeller of
T2 severed the fuselage of T1 approximately 10 feet in front of its horizontal stabilizer. T1’s tail section
was separated
from the rest of the airtanker at that time, rendering it out of control. The pilot of T2 radioed
Palm Springs Approach Control at 1350 PST, declared an emergency, and apprised them of the collision.
T2 landed at the Palm Springs Airport at 1356 PST. The Captain and Copilot of T2 were not injured.
After T1 experienced the tail separation, they lost altitude rapidly. T1 dropped debris for about a mile and
a half until it cut through two power lines and then struck the earth nose first. There was a post-mishap
fire. The Captain and Copilot were fatally injured.
The tail section of T1 was found approximately two and a half miles from the main wreckage site. The
power company observed a power surge at 1343 PST, which was presumably caused by the fuselage of T1
breaking power lines at the mishap site.
T2’s damage consisted of damage to the right wing flap, scrapes and punctures to the retardant tank,
damage to the right wheel compartment, badly “chewed up” propeller blades on the number two engine, a
hole in the left wing, a dented left horizontal stabilizer on the tail, and various other damage.
Turbulence and wind were not believed to be a factor contributing to this mid-air collision.
T1, a DC-4, was manufactured in 1944 and licensed as transport category. They were operating under a
current Forest Service contract. The Captain’s pilot application, dated April 12, 1978, showed that his
qualifications and experience met minimum requirements for the Forest Service contract. His flight time
was listed as 3,000 hours as the PIC of which 1,400 hours were in multi-engine aircraft. He had
accumulated 2,500 hours in aerial dispensing operations and 1,375 hours of multi-engine time in aircraft
over 12,500 pounds maximum certificated gross weight (MCGW). He had a total time of 26 hours in the
DC-4.
T1’s Copilot’s pilot application, dated April 21, 1980, showed that his qualifications and experience met
minimum requirements for the Forest Service
contract. His flight time was listed as 1,500 hours as the PIC
of which 735 hours were in multi-engine aircraft, 730 of those hours were in multi-engine aircraft over
12,500 pounds MCGW. He had a total time of 0 hours in the DC-4 at that time
.
T2, a DC-4 or C-54 G, was manufactured in 1945 and licensed as standard category. They were operating
under a current Office of Aircraft Services (OAS) contract.
T2’s Captain pilot application, dated May 4, 1980, showed that his qualifications and experience met the
minimum contract requirements. His flight time was listed as 16,000 hours as the PIC of which 12,000
hours were in multi-engine aircraft.
11
T2’s Copilot pilot application, dated January 25, 1980, showed that his qualifications and experience met
minimum requirements for the contract. His flight time was listed as 2,970 hours as the PIC of which
2,077 hours were in this category and class.
The investigation concluded that whomever was actually flying T1 permitted the airtanker to collide with
T2, resulting in the loss of the tail of T1, and the subsequent total loss of T1.
QUALITY PHOTO NOT AVAILABLE
12
The Fairchild C-119 airtanker was dispatched from Goleta, California at 0857 hours Pacific Daylight Time
(PDT), July 8, 1981, heading for a fire burning on the Los Padres National Forest. The airtanker arrived at
the fire location and was given direction for the drop by the Incident Commander (IC). The IC instructed
the airtanker pilots to keep the drop high because of steep terrain and snags. They were also instructed to
drop only one-half the retardant, saving the remainder for another run. The airtanker pilots acknowledged
the instructions.
The airtanker pilots notified the IC that they were on final approach. As the airtanker approached the
intended drop area, the IC noted from the sound of the engines that they were “revved up.” He also heard
cracking and popping sounds. When the airtanker came into his sight, the IC and another person noticed
that the drop doors on the airtanker were not open and that the landing gear was retracted.
The IC had worked with this airtanker and its crewmembers on several previous occasions. The IC noted
that the airtanker was lower than he had expected, traveling at an air speed higher than he had observed on
previous drops, and that the airtanker was in a descending attitude. The IC and one other person observed
the airtanker continue past the intended drop site and then suddenly drop vertically approximately 50 to 100
feet. At that moment, the left wing tip (approximately half of the total left wing span) flexed downward,
snapped off, and began cartwheeling along behind the airtanker. The airtanker began to roll left, its nose
began to drop, it began to strike trees, and then it struck ground at 0927 PDT.
The Captain and Copilot were fatally injured upon impact. The aircraft was totally destroyed.
Ground investigation confirmed the loss of the left wing prior to impact. Portions of the left wing, left flap,
left inboard aileron, and approximately 20 feet of intact left wing tip were recovered between 50 to 800 feet
in front of the impact point
.
The terrain consisted of vegetation including Jeffrey pine, Pinon pine, and brush ranging from ten to 80 feet
in height. The slope gradient of the land surface ranged from 40 to 80 percent. Elevation at the top of the
mountain was 6,500 to 6,750 feet. The mishap was located at the 5,250-foot level. The temperature was
70 degrees Fahrenheit and winds were approximately five miles per hour (mph) from the north-northeast.
At the time of the Captain’s Forest Service inspection on June 15, 1981, he had accumulated 7,000 hours of
total flight time, 250 hours of this total time was as Copilot. He was rated for multi-engine aircraft of over
12,500 pounds MCGW and he reported 5,000 hours in this aircraft category. Time in typical terrain
(mountainous) was reported as 5,000 hours.
At the time of the Copilot’s Forest Service inspection on April 21, 1981, he reported his total flight time as
996 hours. 804 of those hours were flown as a Copilot. He had 400 hours in typical terrain.
The Fairchild C-119 airtanker started contract
performance on June 15, 1981, with an accumulated airframe
time of 4,874.4 hours. From that date until July 7, 1981, the airframe had accumulated an additional 40.44
hours of flight time. The maximum amount of flight time on any single day during the 23 previous days of
contract use was three hours and 52 minutes on June 26, 1981.
The airtanker’s maintenance schedule was up to date. This airtanker had a malfunction of the number one
engine at an airport on June 15, 1981. The number one engine was replaced and the airtanker returned to
service on June 18, 1981. On June 26, 1981, this airtanker encountered severe turbulence in Arizona,
which had “ripped” the helmet from the pilot’s head and strew equipment around inside the airtanker. The
Captain and Copilot reportedly later inspected the airtanker for visible damage and “jumped up and down
on the wing and everything seemed all right.” The weight of this airtanker was estimated to be 69,240
pounds at the time the mishap occurred.
Investigation by the National Transportation Safety Board (NTSB) and Forest Service teams showed
definite pre-mishap cracks in the inner left wing aileron bell crank control assembly. The possibility of a
13
bell crank failure could have induced aileron flutter, which in turn could have contributed to wing
destruction causing the wing to separate from the airtanker.
After this mishap, all C119s under contract in this Region were grounded so airworthiness inspections
could be conducted. Three aircraft were inspected and a total of 14 parts in aileron control systems were
found cracked or to have had excessive wear. Three of five bell cranks were found to have cracks. An
Airworthiness Directive (AD) was then issued by the FAA pertaining to prevention of possible wing failure
due to loads induced by “free aileron” on this type of aircraft.
Aerial view of Fairchild C-119 main wreckage.
14
March 5, 1983 found the airtanker, a Douglas B-26 on contract to the Forest Service, dropping retardant
onto fires on the Cherokee National Forest in Tennessee. The morning before, this airtanker and single
pilot contained 3.0 hours of flying. The airtanker had then landed in Knoxville, Tennessee at Tyson Field
and refueled with 400 gallons of 100 octane avgas. The airtanker then departed for its regularly assigned
base at Asheville, North Carolina.
At about 1620 hours Eastern Standard Time (EST), a Forest Service leadplane was dispatched to a fire near
Hubbard’s Fork, Kentucky. This leadplane arrived at the fire at 1700 EST and shortly thereafter another
airtanker from Tyson Field arrived. The fire was in a “blowup situation” and it was necessary for this
airtanker to drop its complete load on one pass over this fire. This airtanker made his retardant drop
without incident and returned to Tyson Field. The late developing fire necessitated a call for additional
firefighting aircraft.
The Douglas B-26 airtanker was dispatched from Asheville, North Carolina ATB at 1715 EST and arrived
on scene at approximately 1745 EST. The airtanker pilot contacted the Forest Service leadplane who was
circling overhead, coordinating firefighting efforts. The airtanker orbited at 3,000 to 3,500 feet mean sea
level (MSL) while the leadplane made a dry run on the fire to evaluate the conditions, type of drop to be
made, and to identify any safety hazards. The two pilots discussed the fire situation and behavior
characteristics and decided what strategy would be used on the retardant drops
.
The airtanker’s first retardant drop on this fire was made utilizing two doors in trail configuration and was
completed without incident. The second pass was again made in standard airtanker-leadplane configuration
(leadplane in front) with a two-door trail drop. According to the leadplane pilot, their strategy had been to
save the last two available doors for any hot spots or blowups that might occur on the fire. After the second
retardant drop, the airtanker initiated a very wide left hand pattern approximately one and one half miles
behind the leadplane.
As the airtanker was flying the left hand pattern, he and the leadplane pilot discussed strategy to be used on
the final drop. The airtanker was then about one mile ahead of the leadplane and was flying at minimum
terrain clearance level. The wind shifted, the “blown-up” area of the fire was visible, and the fire-line
became obvious to both pilots. The last run was to be completed without following the leadplane. The
airtanker pilot commented to the leadplane pilot, “Well, I can see it real good from here and I think I can hit
it from a left hand turn.” The leadplane pilot assumed the airtanker was gong to make a dry run in order to
get a better look at the fire before making the last drop.
Just after the airtanker had leveled his wings from the turn, the leadplane pilot observed what appeared to
be pieces of metal coming loose from the airtanker as it impacted tree tops on the ridgeline. After initial
impact with the trees, the airtanker continued down a hill approximately 1,600 feet to the final impact area.
The mishap occurred at approximately 1800 EST. The pilot was fatally injured.
Witnesses on the ground reported the airtanker had struck trees near the top of a 1,800-foot ridgeline and
plummeted into a ravine 1,600 feet from the initial impact point. They also reported about how low the
aircraft had been at the beginning of the run and that the engines were running smoothly and even increased
in power just prior to the time of impact.
This Douglas B-26 was manufactured as a United States Air Force World War II medium bomber in 1944
and was later converted for use in fighting wildland fires in its civilian version under a
Special
Airworthiness Certificate. It was licensed in the “Restricted” category. All AD’s and service bulletins had
been complied with as of January 22, 1983, the date of its last 100-hour inspection. There were no
significant discrepancies discovered.
A flight plan was not filed and flight following was provided by the London Forest Service Dispatch
Office.
15
The post mishap position of the propeller blades in respect to pitch angle and the propeller blades impact
configuration suggested that the engines were producing power at the time of impact. Examination of the
airframe structure and the cockpit configuration failed to produce any evidence to support a control system
or structural malfunction. All of the instruments were destroyed, but the fuel selectors, engine magneto
switches, propeller controls, and the throttle level positions were all set at normal operating positions.
The pilot possessed an Airline Transport Pilot Certificate (ATP) and had in excess of 4,100 hours of total
flight time. He was type rated in the B-26 and had accumulated 733 hours in this aircraft in more than the
four years he had been working as an airtanker pilot.
He reportedly was a very qualified and skillful pilot. It was noted that on numerous occasions other
leadplane pilots and the aircraft owner had counseled the pilot about getting too low on his retardant drops.
He had been proud of his airtanker abilities/performance and
he frequently exhibited an overzealous
attitude while performing firefighting operations.
Evidence in this mishap also suggested that he flew too low, below the 150 foot authorized drop height.
This maneuver placed the aircraft in a position of insufficient height above the ground, consequently
disallowing sufficient altitude to safely maneuver the aircraft.
The pilot was not wearing contract required personal protective equipment (PPE). His cause of death was
listed as head injuries.
The weather was typical for the spring season. A frontal passage had occurred during the preceding 48
hours and was producing gusty surface winds from 12 to 20 knots with rapid clearing and a temperature of
approximately 70 degrees Fahrenheit. The aviation weather forecasts had predicted these conditions along
with an advisory of moderate to severe turbulence over the mountains.
At the approximate time of the mishap, the Flight Service Station (FSS) reported a ceiling of 15,000 feet
with scattered clouds at 9,000 feet and a visibility of seven miles. All aviation operations conducted on
March 5
th
were performed under Visual Flight Rules (VFR). The leadplane pilot and the two other
airtanker pilots all reported that weather conditions were good at the time they made their retardant drops.
All pilots reported clear to scattered sky conditions, visibility in excess of five miles, and light to moderate
turbulence due to gusty winds.
There were visibility restrictions in certain locations due to smoke from the fire, but ground observers
stated that they could see the aircraft when it struck the treetops. Visual Meteorological Conditions (VMC)
prevailed at the fire scene.
After studying the factual information gathered in the course of the investigation, the investigation team
concluded that the mishap of the airtanker was due to an undetermined cause. After careful review of the
facts and circumstances of this mishap, they had two hypotheses.
Hypothesis A: The pilot allowed the aircraft to descend below the authorized drop height of 150 feet,
thereby placing the aircraft in a position of insufficient height above the ground, consequently disallowing
sufficient altitude to safely maneuver the airtanker.
Hypothesis B: The pilot encountered a wind shear effect or similar phenomenon and could not control the
airtanker sink rate or didn’t notice anything unusual until it was too late to recover and lost control of the
aircraft. The team was unable to verify the existence or nonexistence of a wind shear phenomenon.
QUALITY PHOTO NOT AVAILABLE
16
This OAS contracted and carded Fairchild C-119G (3E) airtanker was flying under the operational control
of the Forest Service on a Forest Service fire on September 16, 1987 when the mishap occurred. It had
been dispatched to a fire about six miles west of Castle Crags State Park, California at 1705 PDT and
departed the Siskiyou County Airport (Montague, California) shortly thereafter.
The C-119G airtanker, another airtanker of the same kind, a leadplane, and an air attack arrived at the fire
at the same time. Two more airtankers followed shortly thereafter. The leadplane identified the target, the
approach and departure routes, indicated the target was at an elevation of 4,500 feet, that the ridge on final
approach was to be crossed at 6,600 feet, advised there was no wind, there was good visibility, and that
there was no turbulence except a “1.5g bump” going across the head of the fire.
The leadplane directed one of the C-119 airtankers to drop first. That airtanker aborted their first run
because of excess speed. On the second pass, it crossed the ridge at a different point, permitting a
somewhat longer final approach. That drop was a
successful one. The run was made through a saddle then
down a creek to the fire some two miles down stream with a planned exit down stream into a larger canyon.
The leadplane then directed the mishap C-119G airtanker to drop next. The mishap airtanker used the same
approach as the first airtanker. The mishap airtanker reached the uphill side of the fire when the crew
reported trouble maintaining proper speed and dropped their retardant on the fire. At about the time the
pilot dropped the retardant, a structural failure occurred and the right wing separated from the airframe
along with the tip of the left wing and the tail booms. The fuselage with both engines and most of the left
wing attached encountered terrain impact and burned as a unit. The time was 1730 PDT.
The Aviation Manager at the Redding Airport sent another leadplane to relieve the leadplane already on
scene and asked the Dispatch Office to recall the remaining airtankers. The Dispatch Office then recalled
the relief leadplane and directed the on-scene leadplane to drop the remaining airtankers.
The on-scene leadplane directed the other C-119G to drop, using the same pattern as the previous two
airtankers. This airtanker again aborted the first run because of excess speed. While this airtanker was
recovering altitude to try again, the on scene leadplane directed another airtanker, a DC-4, to drop. The
DC-4 used the same pattern and successfully dropped retardant on the burning wreckage of the mishap
airtanker, which was about one half of a mile past the fire. The C-119G had just gone around and then
made a successful drop on its second pass. The fourth airtanker at this fire
was also a C-119. The on scene
leadplane and the remaining three airtankers then returned to the airport.
Both pilots and an Airframe and Powerplant (A&P) Mechanic on board were killed.
The Captain was qualified in the C-119 as an Initial Attack airtanker pilot and had been properly approved
by OAS in the Alaska Region. He had limited experience in airtanker work in the typical terrain of the
mishap. He had accumulated 12,943.1 hours of total flight time, 12,143.4 of these hours were logged as the
PIC. 1,286.6 hours were recorded as the PIC time in type, 515 hours as the PIC in low-level operations,
3,501.6 hours as the PIC in aircraft over 12,500 pounds MCGW, 85.4 hours as the PIC of
Airtanker/Dispensing Operations, and five hours as the
PIC in initial attack at the time of his qualification
inspection on April 16, 1987.
The Copilot was a qualified airtanker Copilot, and had been properly approved by the OAS in the Alaska
Region. He had 1,652 hours of total flight time. He reported 1,205 hours as the PIC in airplane, 0 hours as
the PIC time in type, 60 hours as the PIC in low-level operations, 0 hours of time as the PIC in aircraft over
12,500 pounds MCGW, and 0 hours time as the PIC in airtanker/dispensing operations on April 22, 1987.
The A&P Mechanic was serving his first season with this company and was apparently on board
because
the airtanker had been dispatched from the Siskiyou County Airport with instructions to land at the
Redding Airport. Neither the Contracting Officer Representative (COR) nor the Contracting Officer (CO)
had approved him to accompany the flight crew on airtanker flights. The CO would probably have
approved this had a request been made.
17
The leadplane pilot was qualified. The direction and coordination of the four airtankers dropping on the
fire was in accordance with standard procedures.
The Fairchild C-119G (3E) airtanker was approved under an OAS contract in the Alaska Region on May
25, 1987. It was ramp-checked by Forest Service Inspectors prior to service on fires in the Pacific
Southwest Region.
There was no evidence of any unresolved mechanical problem with the airtanker immediately prior to the
mishap. The airtanker was within maximum take-off weight. There was no reason to suspect that the
center-of-gravity limits had been exceeded. The maximum zero fuel weight was most likely exceeded by
several thousand pounds.
The retardant load had been dropped immediately prior to the mishap. At the time of impact, there
were
approximately 1,075 gallons of fuel on board, the landing gear and flaps were retracted or almost retracted,
and the engines were running, but not developing significant power. The airtanker had almost certainly
been substantially exceeding normal drop speed at the time the retardant was dropped. There was no
evidence of failure of any wing structure component by reason of fatigue, cracks, corrosion, divergent
control surface flutter, casting defects, or other deficiencies. All fractures were tensile or shear failures.
The visibility conditions in the fire area were excellent. The air was smooth except for a “bump” passing
by the fire. Terrain features associated with the retardant drop run on the fire were typical for this
geographical area in northern California. The route chosen for the drop run required the airtankers to
descend 2,000 feet within about two miles to make an effective drop on the fire. A ground crew was
working this fire and although there were near misses, no one on the ground was injured.
The Captain of the third C-119G airtanker, who had been the first to attempt a drop, stated that after the
aborted run he went around and made a longer run on the fire. All of the C-119G Captains stated that this
(fire zone) was a hole and that slowing down to the correct speed was risky and dangerous. They all stated
that they had done just that.
The mishap investigation team concluded that the airtanker was subjected to excessive aerodynamic loads,
which led to a catastrophic structural failure of the wings due to excessive speed and probable excessive
pitch-up at or immediately after dropping the retardant.
Fairchild C-119G (3E) main wreckage.
18
On September 29, 1990, a civilian general aviation Cessna 172 encountered a mishap during search and
rescue training over the Hood Canal District of the Olympic National Forest in Washington. The wreckage
was located on the east side of Wynoochee Lake. A post-mishap fire began to burn. The Forest was
informed of the fire the morning of September 30
th.
The District covered initial attack of this fire, which
began to burn vigorously around 1130 PDT. Between 1130 PDT and 1230 PDT, two 20 person fire crews,
a helicopter with a bucket, an air space closure, and an airtanker retardant drop were ordered.
A leadplane and a Lockheed Neptune P2V-7 airtanker were then dispatched from the Wenatchee ATB with
estimated times of arrival (ETA’s) over the fire of 1330 PDT and 1340 PDT respectively. The leadplane
did arrive at the fire at 1330 PDT and contacted the Incident Commander (IC). The IC told him to contact
Mr. X for drop instructions. The airtanker crew, leadplane pilot, and Mr. X discussed drop locations.
The leadplane made one run from the north to the south over the determined drop location, a pattern that
was decided as unacceptable. The leadplane then made two more runs and he and the airtanker crew
agreed on a run from the south to the north. The leadplane informed Mr. X and the airtanker crew that the
drop would and should be high because of terrain considerations. The leadplane pilot said he wanted the
airtanker to drop half their retardant load, single door trail with three tenths of a second delay, so that if
they missed due to the high drop, they would be able to make another run. The airtanker made the run and
dropped the retardant on target. The airtanker then immediately
impacted a ridge before the retardant
dropped completely hit the ground.
The airtanker impacted a log landing area with the mid section of its fuselage. The tank doors were not
closed. One tank door was buried vertically upon initial impact. The airtanker began breaking up. The
outer right wing and jet engine were torn off upon hitting a stump piling area on the edge of the log
landing. The airtanker continued across the log landing and the tail section separated. This section came to
rest approximately 250 feet down slope from where the airtanker initially impacted terrain. The cockpit
and remaining fuselage continued down the slope, became inverted, and pointed back up towards the
impact point. The remainder of the right wing, right reciprocating engine, and the left wing with both
engines separated continued down slope from the cockpit fuselage.
Both airtanker pilots suffered fatal injuries. The time was about 1359 PDT.
The terrain the retardant drop was requested on was wooded and mountainous. The ground was hard with
an 80 percent slope. The obstacle struck before principal impact was a “log landing.”
A review of the activities of both the Captain and Copilot conducted for the previous 36-hour period prior
to the mishap revealed an established normal daily routine for both individuals.
The Captain had accumulated 14,723 hours of total flight time. 11,618 of these hours were as the PIC,
1,312 hours as the PIC in type, 5,669 hours plus as the PIC in aircraft over 12,500 pounds MCGW, and
1,868 hours plus as the PIC of Airtanker/Dispensing Operations by the day of the mishap. The Copilot had
46 hours dual instruction in make and model. He had accumulated 3,090 hours of total flight time, 2,600 of
those hours as the PIC by the day of the mishap.
Wreckage investigation revealed that the airtanker’s two reciprocating engines were operating at or near
full power. The jet engines (jet assist) were running, but were not at full power. Jet engine indications
concluded they were at 40 percent or idle. Jet engine actuating rods when operating at 100 percent power
are measured at 13 inches. Both of this airtankers’ jet engine actuating rods were measured post-mishap at
7.5 inches. The varicam system was found to be within normal operating range.
The nose gear was found in the retracted position, which indicated the airtanker crew had started the
landing gear up. On this model Lockheed, the P2V, the nose gear would have come up first, followed by
the main landing gear. The investigation team concluded the airtanker crew had used the landing gear to
keep from building up too much speed when
dropping down from a 2,400-foot saddle to the drop site at
approximately 1,800 feet.
19
In addition, the crew had the flaps fully extended, the flapjack screw follower was found to be two to three
inches from the end of travel, which would have been normal for making the retardant drop. Flaps would
have allowed for a more stable lower airspeed while the crew used power when they approached the target
drop zone for the retardant drop.
The probable cause of this mishap was that the pilot maneuvered the airtanker in a manner that he was
extremely low and slow, with landing gear and flaps extended, and did not use additional jet engine thrust
available to clear the ridge. The pilot had misjudged the short steep canyon and was not able to recover
sufficient airspeed to exit the drop pattern safely. The pilot had dropped one half of their retardant on the
target and did not jettison the other half of the load to avoid hitting the ridge.
Lockheed P2V-7 airtanker after impact and beginning to break up.
Black and white photo taken by "Daily World.”
20
October 16, 1991 was a repositioning day for the Lockheed P-3A ‘Orion’ airtanker under contract to the
Forest Service. The airtanker had been dispatched from its base in Santa Barbara, California to Missoula,
Montana to support fire suppression efforts involving a number of large fires in the Northern Region.
The Captain and Copilot departed in VFR conditions at 1605 PDT. Their departure was reported to the
National Incident Coordination Center (NICC) in Boise, Idaho with an ETA of 1950 MDT. They departed
Santa Barbara with their normal fuel load of approximately 20,000 pounds and topped off oxygen tanks.
While still in the area controlled by the Oakland FAA Air Route Traffic Control Center (ARTCC), the crew
requested and received an Instrument Flight Rules (IFR) clearance. They were assigned an altitude of
23,000 feet. The Orion proceeded uneventfully and was handed off to the Approach Controller at Missoula
(MSO). MSO Approach did not have, at that time, terminal radar equipment that covered their entire area
of responsibility. At first contact with MSO Approach, the Orion was 26 miles southeast of the Missoula
International Airport and descending to 12,000 feet. At approximately this time, the crew reported to the
Forest Service Aviation Coordinator at MSO that they were 15 minutes from the airport. This message was
then relayed to the NICC.
In the course of several exchanges between the Orion and the MSO Approach Controller, it was disclosed
and confirmed that the Orion’s flight crew did not have the approach plate (or chart) depicting the
published approach procedure for the Victor Omnidirectional Range-Distance Measuring Equipment
(VOR-DME) Bravo (B) approach, which was the approach in use for aircraft arriving from the south.
Clearance was nevertheless offered and accepted and the controller provided the information as the Orion
crew began to execute the VOR-DME B approach.
At this time, the cloud bases at the MSO Airport were at about 7,900 feet and other aircraft making
instrument approaches there were descending through 8,000 feet, canceling their IFR flight plans and
making visual approaches to the airport for landing. Since the Orion’s crew was able to monitor these radio
communications/transmissions on the same frequency, they were probably counting on doing the same.
At this time, there were very strong winds and moderate to severe turbulence reported at altitudes above
8,000 feet that increased with altitude in the MSO area. In addition to turbulence, the Orion crew
contended with effects of flying at high
altitudes, using oxygen in an unheated and un-pressurized aircraft
for more than two hours.
At some point in the initial phase of the approach, some confusion as to what heading to fly apparently
occurred and the airtanker turned back toward the south, away from MSO. By this time the controller had
authorized descent to 8,600 feet on an approximate heading of 200 degrees magnetic.
MSO Approach received notification by Salt Lake City ARTCC (Center) that this airtanker was west of the
course consistent with the approach procedure and subsequent notification that the airtanker had
disappeared off Center’s radar screen. Repeated attempts to contact the Orion crew failed and MSO
Approach notified the County Sheriff’s office, the Forest Service, and other agencies that the aircraft was
missing and presumed down. Search and rescue attempts were not able to detect an Emergency Locator
Transmitter (ELT) signal. The mishap site was located the following day. The Orion crew had died
instantly of multiple massive injuries.
The Orion flight crew was current and qualified in this aircraft and for the mission. The Captain had
accumulated 8,868 hours of total flight time, 8,106 hours as the PIC, 129 hours PIC time in type, 5,138
hours as the PIC in low level (below 500’above ground level (AGL)), and 2,825 hours as the PIC in typical
terrain (mountainous). His instrument time on the date of contract inspection, May 31, 1991, contained 231
hours of actual and hood time combined.
The Copilot had accumulated 3,087 hours total flight time, 2,288 hours as the PIC. His instrument time
consisted of 174 hours of combined actual and hood. He declared 180 hours as the PIC in the Type 1 “Low
21
Level” environment, and 180 hours as the PIC in typical terrain (mountainous) on the date of his contract
inspection, April 29, 1991.
Some of the findings of the investigation team are noted here; however, this is not a complete list of
findings.
The airtanker was airworthy with no evidence of malfunctions. The airtanker did not have an exhausted
fuel supply. There was a post mishap fire that burned itself out quickly.
The crew had been subjected to the environmental stress of operating the majority of the flight at flight
level 23,000 feet in an un-pressurized and unheated cockpit with outside temperatures below –20 degrees
Centigrade while wearing oxygen masks.
Terminal weather at MSO was VMC. Weather affecting the initial and intermediate segments of
instrument approaches into MSO was Instrument Meteorological Conditions (IMC). There was
reportedly
strong westerly winds and considerable turbulence between 8,000 to 15,000 feet, precipitation in the form
of snow, and mountain top obscuration around the MSO airport.
The MSO Airport is located in a valley surrounded by mountainous terrain with high rims. The National
Weather Service (NWS) reported 100-knot winds at 12,000 feet. The elevation of the mishap site was
approximately 8,500 feet MSL.
The airspace under the control of MSO Approach Control was a non-radar environment. Therefore, the
controller on duty had to rely on the airtanker crew informing him of their position and altitude during the
approach phase of their flight.
MSO Approach Control issued and the Orion crew accepted an instrument approach clearance for the
VOR-DME B approach with mutual understanding that the Orion crew did not have the published VOR-
DME B approach procedure on board.
Approach transmitted only sufficient information to enable the Orion crew to position the airtanker onto the
initial stages of the approach. Further instructions to complete the approach were to follow. The VOR-
DME B approach instructions issued to the Orion crew by the controller, though technically correct, would
have been difficult to follow given the position of the airtanker at first contact with Approach.
The Orion crew transmitted a query to Approach Control concerning the final approach heading and the
reply transmitted back to them could not have adequately fulfilled the intent of the question or aided the
crew in their attempt to position the airtanker on a portion of the published procedure.
A significant interval of time elapsed after the warning from Center that the airtanker could possibly be
outside protected airspace before Approach issued a climb clearance. The Orion crew deviated from the
clearance instructions issued by the Approach Controller. Protected airspace provided in the instrument
approach procedures diminished rapidly if deviated from.
Federal Aviation Regulations (FARs) and the “7110.65 Controllers Handbook” do not prohibit Air Traffic
Controllers from providing an instrument approach clearance to pilots who do not have the published
approach charts. FARs and provisions of the Forest Service Airtanker Contract required that aircrews have
all enroute and letdown charts appropriate for their flight.
The VOR navaid on which the VOR DME-B approach is predicated was checked for proper operations and
was operating to specifications satisfactorily the day following the mishap.
The winds and turbulence in the Missoula area and the Orion crew’s inability to refer to the appropriate
published approach chart compounded the level of difficulty during the approach sequence.
22
The aircraft impacted terrain during this instrument approach.
Lockheed P-3A Orion main wreckage site.
23
This Douglas DC-7B airtanker had been operating from Stockton ATB, California and had made several
drops of retardant on the southeast edge of a fire on the El Dorado National Forest.
Their first mission on October 1, 1992, had begun at 0833 PDT. Their fourth mission had them departing
the ATB at 1156 PDT. Their departure was immediately followed by a Lockheed SP2H enroute to the
same fire. The DC-7B arrived in the fire vicinity at an elevation of about 6,500 feet MSL at 1220 PDT.
Air attack briefed the DC-7B’s two-person flight crew for their retardant drop. Air attack was flying at
approximately 7,500 feet MSL. The planned drop was to be made from north to south about one mile west
of the upper dam on the
reservoir. It was to be the airtanker’s first drop in this particular location. The
visibility was good, in excess of ten miles, and turbulence was reported as mild, but bumpy. The area over
the lake to the east of the drop pattern was experiencing reduced visibility due to smoke.
According to occupants of the second airtanker, the DC-7B made a turn around the fire and was descending
northbound for a drop out of a right hand pattern when the DC-7B Captain indicated that he wanted to
depart the pattern as he had a problem with an engine. He suggested the second airtanker perform the
intended drop while he worked with his engine problem. The second airtanker then received attention from
air attack
and began a circle to fly a pattern similar to the pattern the DC-7B had flown.
Shortly thereafter, air attack asked the DC-7B if he needed to abort (drop) his load of retardant. That
Captain replied that he might have to if he couldn’t solve his engine problem. All communications were
normal. Air attack was operating without leadplane assistance as the leadplane had departed the scene for
fuel a few minutes before, instructing air attack to perform drops on the west side of the reservoir. Another
leadplane was about six minutes out.
The mishap airtanker was reported to be descending at about 6,000 feet MSL heading in a north-
northwesterly direction after departing the drop pattern, with no visible signs of engine problems and no
indication of concern present in his radio transmissions. The DC-7B continued northbound toward gently
rising terrain about two miles from the intended drop site and was next observed heading in an easterly
direction and low to the ground. The airtanker was reported to be in a sharply pitched up attitude prior to
dropping its retardant. Air attack reported that he observed the retardant start and stop, but did not know if
a full load had been dropped. He said the load was continuous. The DC-7B was then reported to fall off on
the right wing as it descended steeply toward the ground. During this sequence, the Captain
transmitted on
the radio, “We’re going in, we’re going in.”
It was at this point that tree strikes occurred which removed the horizontal stabilizers and elevators from
the tail of the airtanker. This entire sequence took place within the span of about 60 seconds. The airtanker
then went behind a ridge and white smoke was observed rising from the site. Air attack declared a mayday
and flew immediately to the site, taking approximately one minute to arrive on scene.
The airtanker had impacted the ground in steep terrain at an elevation of approximately 5,100 feet MSL.
Some of the wreckage was deposited in a creek bottom and the remainder was located on an adjacent
south-facing slope. Both the Captain and Copilot were fatally injured. The aircraft was totally destroyed.
The time was noted as 1225 PDT. A post-mishap fire consumed 20 acres before
it was contained.
From a distance, several witnesses observed the airtanker pitch up sharply, very close to the ground and
observed retardant being released from the airtanker prior to it going out of sight behind a ridge.
The Captain was properly certificated and initial attack qualified to perform retardant missions on fires. He
operated the airtanker within established flight and duty limitations. He completed two mandatory days off
on September 22
nd
and 29
th
. On May 13, 1992, the Captain possessed 8,225 hours total flight time, 6,850
of this time was as the PIC. In the previous 12 months, he had flown 17.5 hours as the PIC, 15 hours of
which were in the previous 60 days. He had accumulated 1,106 hours in type, 500 hours in fire
surveillance, 2,100 hours of low level flight (below 500 feet AGL), 1,106 hours as the PIC in aircraft over
12,500 pounds MCGW, 1,000 hours as the PIC in airtanker/dispensing operations, 5,200 hours as the PIC
in multi-engine aircraft, and 1,500 hours in typical terrain (mountainous).
24
On May 13, 1992, the Copilot reported a total flight time of 2,445 hours, 2,315 hours of which were as the
PIC. He had 0 hours in airtanker/dispensing operations, 199 hours as the PIC in multi-engine land aircraft,
five hours of PIC time in the previous 12 months, 0 hours of PIC time in the previous six months, 120
hours in fire surveillance operations, 0 hours as the PIC in low level flight, 0 PIC hours in aircraft over
12,500 MCGW, and 368 hours in typical terrain. He was qualified as an airtanker Copilot. His most recent
day off was September 29
th
.
The airtanker was properly inspected, properly carded, and was carrying 2,672 gallons of GTS-R retardant
at the time of the mishap. Information from the investigation revealed that no propellers were feathered
and all were turning at the time of impact. At least one or more engines were determined to be producing
significant power.
The weather was clear. Light turbulence and good visibility were reported in the area of the drop zone. Air
attack reported good visibility over the mishap site as well. Two ground personnel in the area reported
smoke drifting in from the spot fire being worked and that horizontal visibility was poor in smoke.
Therefore, localized smoke near ridges may have restricted horizontal visibility.
The terrain was moderately steep, logged over in the previous ten years, and populated with a mixed and
uneven aged stand of Alder, Red Fir, Cedar, Sugar Pine, and Manzanita trees. Terrain was a factor in the
mishap.
The investigation team determined that the DC-7B impacted Ponderosa Pine trees at approximately 5,400
feet MSL prior to ground impact. Ground impact occurred approximately 1,500 feet from the first point of
vegetation impact. Major portions of both horizontal stabilizers, both elevators, and some
retardant tank
gating system components were found between the initial impact point and the actual wreckage location at
4,900 feet MSL.
The causal factor of this mishap was the pilot’s preoccupation, inattention, or possible distraction while
operating the airtanker in close proximity to terrain. Contributing factors included: 1) Cockpit/Crew
Management, 2) The pilots failed to recognize the severity of the situation and were reluctant to abort their
retardant load, and 3) The fuselage struck vegetation.
Overview of main Douglas DC-7B mishap site.
25
The Lolo National Forest in Montana had a large fire incident occurring on July 29, 1994. Many resources
were being utilized including smokejumpers, airtankers, and leadplanes. We join the scenario well into the
retardant dropping stage.
Smokejumpers on the fire had requested drops straight down the hill. The leadplane (with a leadplane
trainee and instructor on board) thought that a run straight down the hill would require the airtankers to
descend too steeply and did not approve that pattern. Instead, airtankers were flying a counterclockwise
pattern and were making their runs more or less parallel to the hillside, from southeast to northwest, and
then maneuvering out over the valley.
The leadplane was communicating with the ground crew on the radio “smokejumper net” and with the
airtankers and a helicopter in the area on an aviation very high frequency amplitude modulation (VHF-AM)
frequency. The leadplane needed to depart the fire to return to Missoula for fuel and informed the ground
crew that another leadplane pilot would be relieving them in the same aircraft after refueling.
While the leadplane was refueling, the fire became quite active and several spot fires occurred on a small
finger ridge 200 yards northwest of the main fire. When the leadplane had left, the smokejumpers
understood that one of the airtankers,
a Lockheed P2V-7 Neptune, would be returning to the fire with
another load. They had a particular spot fire that was troublesome and they wanted that retardant dropped
on it.
Meanwhile, after refueling, the leadplane was appropriately diverted to another group of fires. There were
no other leadplanes available in Missoula. The airtanker Captain was advised that a leadplane would not be
able to assist with his drop and he agreed, before takeoff from Missoula, to make the drop without
leadplane assistance. The Captain was both qualified and approved to fly the drop without a leadplane.
Once the Lockheed P2V-7 Neptune arrived over the fire, they flew in a high counterclockwise pattern, as
before. After some radio congestion and a frequency change, the flight crew was able to contact the
smokejumpers on the ground. The airtanker crew identified which spot fire the smokejumpers wanted the
drop on and agreed to make the run. The smokejumper requested the airtanker to make a half-load drop
downhill (southwest). The airtanker departed from the orbit and flew northeasterly, entering the drainage.
About one mile from the fire and about 1,000 feet over a point between the creek and the ridge to the north
leading up to a peak, the airtanker was seen to drop part of its retardant load over a patch of sparse timber.
The airtanker then turned somewhat to the right toward the ridge southeast of the creek. Before reaching
that ridge it turned left again to parallel the creek and started climbing up, what, from their viewpoint,
would have been the right side of the drainage, at an altitude below the tops of the ridges on both sides and
in front of them.
As they approached the upper end of the drainage the Captain began a left 180-degree turn, still at an
altitude below the ridges around him. At some point during his maneuvering he radioed the smokejumper
to ask “Is anyone down there?” The smokejumper replied to the negative and the Captain called “Turning
final.” Part way around the turn and perhaps ten seconds later, the Captain called “Tanker – is going in.”
He repeated it twice, rolled wings level flying toward the ridge, pulled up hard, and impacted terrain about
350 feet below the ridge top.
A helicopter was at the mishap scene immediately and once there, reported the mishap to dispatch. He
advised them there was little likelihood of survivors and that the post-crash fire had ignited a rapidly
growing wildland fire. Two airtankers and a leadplane were dispatched to the site and two loads of
retardant were dropped on the wreckage location within 30 minutes of the mishap. Airtanker operations at
the ATB were then shut down.
Both the Captain and the Copilot survived the initial impact, exited the airtanker, and then died at the
mishap site as a result of thermal injuries. Immediate post-mishap actions needed to address the possible
rescue of the airtanker crew were rapid and appropriate.
26
The District Fire Management Officer (FMO) and a search and rescue specialist from the County Sheriff’s
Office flew to the mishap site in a helicopter about 90 minutes after the mishap. They decided that the state
of the wildland fire ignited by the crash, the weather, fuels, and terrain in the area together with difficult
access and lack of potential safety zones precluded staffing the fire and, when balanced against the
unlikelihood of survivors, precluded ground search and rescue operations as well.
An alternative decision to attempt immediate access to the site would have placed personnel at
unacceptable risk and the aircrew still would not have survived. The low suppression priority of the
post-
crash fire established by the Ranger District on July 29
th
and maintained through July 30
th
by the incident
management team resulted in no direct suppression actions on the mishap site fire through July 30
th
, other
than the two retardant drops immediately following the mishap. Fire suppression actions on the post-crash
fire on July 31
st
and August 1
st
were appropriately aggressive.
Visibility on the original fire had been good and smoke was reportedly not a problem. The air was smooth
with no “sinkers,” but there was some convection from ground heating. Density altitude from the target
fire vicinity was high enough to materially effect aircraft performance. There was nothing remarkable about
the fire that the retardant drops were being made on.
The airtanker was airworthy at the time of takeoff on the mishap flight and the fuel on board at takeoff was
adequate for the planned flight. The airtanker was configured for best climb performance prior to the
mishap. The airtanker had part of the retardant load on board at time of ground impact. Presence of a
leadplane on scene for the planned drop would probably have averted the mishap.
The investigation team determined this following sequence of events leading up to the impact point. The
Captain presumably elected to fly a flight path northeast into the drainage as requested by the
smokejumpers. As the Captain began the flight path and programmed his tank doors for the requested half-
load drop, something went wrong and part of the retardant was dropped. The problem could have been: 1.
The airtanker tank and gating system malfunctioned as it was being programmed and one or more doors
opened without command (Most probable). 2. The Captain inadvertently touched the drop switch on his
control yoke after selecting and arming the three doors required for a half-load drop and dropped one or
more doors (Moderately probable). 3. The Captain saw that the planned drop pattern would require a hard
climb and dropped part of the retardant load to enhance climb performance (Least probable).
Regardless, the flight crew was distracted during the retardant drop and were further into the drainage at a
lower altitude than anticipated when the Captain regained situational awareness. He applied full power to
gain airspeed and then began a climbing left turn starting along the right side of the drainage. About one-
third of the way around the turn and after calling “turning final” he recognized that there was insufficient
room within the drainage to complete the run, rolled wings level, flew toward the ridge and pitched up.
The airtanker failed to climb high enough to clear the ridge and impacted approximately 350 to 400 feet
below the ridge top. As stated, part of the retardant load was still aboard.
The Captain was worn down and fatigued. Both pilots were qualified and approved for the mission.
On January 21, 1994, the date of his contract inspection, the Captain was highly experienced with 5,118
hours total flight time, 2,292 hours of typical terrain (mountainous), 2,650 plus hours as the PIC
Airtanker/Dispensing Operations, and 2,202 hours time in type.
The Copilot had 4,500 hours total flight time, 1,500 hours as the PIC in typical terrain (mountainous), 0
hours as the PIC Airtanker/Dispensing Operations, and 0 PIC hours in type on April 5, 1994, the date of his
contract inspection. These pilots had crewed the airtanker together long enough to presumably develop
reasonable cockpit duty coordination (Crew Resource Management (CRM)).
27
This photo of the Lockheed P2V-7 Neptune was taken the day after the mishap, July 30, 1994.
28
This particular Lockheed C-130A had a history dating back to December of 1957 when she was delivered
to the US Air Force. In April of 1959, she was modified and became a C-130A-II to perform electronic
reconnaissance missions. In September of 1964, she was de-modified and reconfigured as a "near standard
C-130A" and transferred to the US Air National Guard. In August of 1986, the aircraft was transferred to
the Davis-Monthan Air Force Base in Tucson, Arizona for storage. In June of 1988, the airtanker was
removed from storage. In June of 1990, she underwent modifications to become a restricted category
firefighting aircraft, which was approved per an FAA Form 337. A Restricted Category Special
Airworthiness Certificate, which authorized aerial dispensing of fire retardant, was issued in May of 1990.
This Lockheed C-130A received an eddy current inspection, which had been completed in April of 1991.
All parts tested met the inspection standard
. She endured an entire progressive inspection cycle on April
22, 1994. She was returned to service following that inspection. This inspection program was an FAA
approved and authorized airplane inspection program (AAIP). On July 17, 1994, the operator completed a
“Day Off Inspection” (seven day check), which included the mechanics initialed item No. 20 b, "Check dry
bay area for leaks, fuel press. On." The records of subsequent checks were kept onboard the airtanker.
The California Division of Forestry (CDF) requested an airtanker to respond to a fire burning near the
Tehachapi Mountains on August 13, 1994. This particular civilian model Lockheed C-130A, on lease to
the Forest Service as a public use aircraft, responded to the call from the Hemet-Ryan Airport in California
at 1310 PDT.
Forest Service Dispatchers gave the C-130A’s three-person flight crew information that included magnetic
direction to the fire and distance from the departure airport, along with the latitude and longitude of the
fire's location. The airtanker operator reported that the flight crew was familiar with the area, the airtanker
was equipped with a global positioning system (GPS), and a company flight plan had been filed for the
operation. The flight was conducted under VFR in VMC, and they were flight following on frequency
124.55 with the “High Desert Terminal Radar Approach Control (TRACON)” (Joshua/Ontario Approach
Control (Approach)).
All communications had been routine with no indication of any in-flight problems. The flight crew had
been responding to radio calls without delay or difficulty until after 1330 PDT. It was at that time the pilot
had reported to Approach that he intended to "go straight for the next 42 miles" when he was asked to say
his destination. The assigned mission was to respond to a reported fire in the mountains. Air traffic control
communication tapes revealed two unidentifiable transmissions: one of an unintelligible squeal, followed
by a brief expletive at 1331 PDT.
Witnesses in the vicinity of the San Gabriel Mountains reported seeing the airtanker in level flight, on a
west-northwesterly heading, when they saw a bright orange flash occur near a wing root. The first flash was
reportedly followed about one second later by a much larger, darker orange fireball accompanied by black
smoke. At that time, witnesses stated that the right main wing separated from the airtanker and the airtanker
began to roll. Both the separated right wing and remaining fuselage impacted on the north face of a ridge in
the vicinity of a canyon at about the 6,500-foot level of a mountain
.
Witnesses stated that the ground impact of the main wing and fuselage resulted in an additional fireball and
explosion with a column of black smoke, causing several small brush fires. At least one witness stated that
the smoke from the ground fire rose vertically in an undisturbed column.
The mishap site was located along an imaginary line connecting the Hemet-Ryan Airport and Tehachapi,
California in steep mountainous terrain, near Pearblossom, California. Firefighting helicopters responded
to the
mishap site, dumping water directly on the wreckage and surrounding area. In spite of those efforts,
the wreckage continued to smolder for over 24 hours. All three crewmembers were fatally injured and the
airtanker was destroyed.
29
The Captain, Copilot, and Flight Engineer were rated in the aircraft and had current flight experience in the
Lockheed C-130A. According to FAA inspectors, at the time of the mishap, the flight was being operated
in accordance with applicable FARs.
The investigation team gathered what they could from the remains of the wreckage. A total of six center
wing pieces, five pieces of the upper wing surface, and one piece of stringer were found approximately
1,000 feet in advance of the separated main wing. Numerous pieces of one inch thick yellow Styrofoam, a
green interior wing panel, and a torn portion of a fuel cell liner were also found in the same general area.
None of this debris had been involved in the resulting ground fire. The Styrofoam material was reported to
have been located beneath the auxiliary fuel cell. Portions of the Styrofoam exhibited evidence of surface
charring. Light sooting of the wing pieces was consistent with normal service.
A crush on the separated right wing components indicated a near level attitude at impact. The
identification was made by serial numbered components recorded as being located on the right side of the
airtanker. Examination of the debris showed the outline of a burned and melted main wing structure
extending from the right wing tip to a section inboard of the number three engine nacelle. The ground fire
had melted or consumed all fracture surfaces on the inboard portion.
A tear down inspection of the number three and four engines showed no evidence of rotational scarring.
Although the supporting structure was fractured or consumed by fire, the engines still maintained their
relative positions on the right wing. The persistent odor of ammonia was detected in and about the number
three engine.
Both the number three and four propellers and hubs were found separated from the engines. The number
three
propeller was found in the feathered position while the number four propeller was found in reverse.
There was no bending, twisting, or leading edge damage on any blade from either the number three or four
hubs. Two blades from the number three hub had been consumed by fire up to the blade root.
The number one and two engines were recovered and both exhibited evidence of rotational scarring. Both
engines were displaced from their position relative to the left wing. Crush damage on the engine cases
indicated a near 90-degree terrain impact angle on both engines. The number one and two propellers and
hubs were separated from the engines. None of the number one or two propeller components were
recovered.
The main fuselage and remaining left wing impacted a rising terrain finger. The impact resulted in major
structural collapse and disintegration and was accompanied by a post crash fire. The cockpit area was
identified, but efforts to access the interior portion were unsuccessful. Attempts at an aerial recovery of the
cockpit were also unsuccessful and resulted in disintegration of the structure.
Investigators estimated that at the time of the mishap, the airtanker was within weight and balance
limitations and had sufficient fuel to complete the planned flight. The airtanker’s encoding altimeter was
indicating 7,800 feet MSL.
Examination of a section of the center wing section, which was found early in the debris path, submitted to
the Materials Directorate at Wright-Patterson Air Force Base for analysis disclosed no evidence of a
lightning strike. None of the fuel probes from the airtanker were identified or recovered.
The investigation team covered more research into the history of this Lockheed C-130A and others like her.
The US Air Force reported that the fuel
systems in C-130A aircraft had experienced fuel leaks due to O-
ring failure. The Air Force did not track the rate of O-ring failures associated with the fuel system.
Lockheed engineers confirmed that report, saying that while O-ring failure was a relatively rare event, it
did occur. According to the Air Force, there had been no known C-130A mishaps in which an external fuel
leak was determined to be the probable cause.
According to Lockheed, failures that had occurred were the result of fuel line flexing or thermal expansion.
They reported that a failure was more likely to occur in a fuel line coupling as opposed to a fuel valve,
30
although the possibility existed for both. They stated that an O-ring failure could range from seeping or
dripping, and occurring over time, up to a failure that would result in a sudden high-pressure spray. They
expressed the opinion that prolonged storage could result in the O-rings drying out or shrinking. They also
acknowledged that the flight profile of aerial firefighting resulted in wing flexing.
A review of maintenance procedures, followed by both the Air Force and the contracted operator and
confirmed by Lockheed, revealed that O-rings were an on-condition item and not life limited. Lockheed
did report that once O-rings were removed, they were not to be reused. A review of maintenance records of
the accident airtanker did not identify any reported fuel leaks or the removal or replacement of any fuel
line, coupling, or valve. According to the contract operator's records, an inspection of the fuel system was
completed on April 22, 1994. The
contract operator reported that an item on the preflight inspection of the
airtanker specified checking the dry bay for fuel odor.
The fuel system of the C-130A is pressurized to 15 to 17 per square inch (psi) for the lines that transfer fuel
from the main fuel tanks to the engine. Cross-feed lines that transfer fuel from the main tanks in the
opposite wing are pressurized to 15 to 17 psi when utilized. The fuel valves in the C-130A operate on a 28-
volt direct current (dc) single-phase circuit. The valve motors are powered only when the valves are in
transit to open or close; however, the cannon plugs are powered whenever dc power is energized. The
external cannon plugs on the valves are not shielded. The electrical wiring is open within the
corresponding wing section and is in proximity to the fuel system. Lockheed reported that there had been
some history of insulation chaffing or cracking, but did not report any known incidents or mishaps in which
an electrical short had contributed to a fuel-fed fire.
US Air Force T.O. 1C-130A-1 stated that external fuel leaks presented a fire hazard if the leak was in the
proximity of an engine. If a leak occurred, it was
recommended that an emergency be declared and that the
aircraft land at the nearest airfield with sufficient runway to complete the landing roll without use of
reverse thrust. Lockheed reported that with sufficient fuel leaking in the dry bay, it would be possible for
fuel to drain through the engine pylon and into the engine nacelle. The hot section of the number three
engine is located below the number three dry bay. The tattletale drain for the dry bay exited out of the
lower engine nacelle forward of the hot section.
According to a publication of the US Air Force Systems Command at Wright-Patterson Air Force Base in
Ohio, the fuel used in the airtanker, Jet-A1, had a flash point of 40 degrees Celsius (100 degrees
Fahrenheit).
Lockheed reported that in 1978, a C-130A experienced an in-flight fire and explosion, which resulted in a
wing separation due to a lightning strike on a fuel probe. According to a readout from the Bureau of Land
Management's (BLM) Automatic Lightning Detection System (ALDS), there was lightning activity in the
area of the mishap site at the time of the mishap. Witnesses both on the ground and in the air near the site
reported that the airtanker was clear of clouds and that there was no visible electrical activity at the time of
the in-flight explosion.
This information was gathered from the NTSB report LAX94FA323.
QUALITY PHOTO NOT AVAILABLE
31
On the morning of June 21, 1995, eight airtankers, eight helicopters, an air attack aircraft, and a leadplane
were operating on a fire 28 miles easterly from the Ramona Airport in California. The weather was clear
and warm, but typically hazy at the airport and toward the fire area.
A few minutes before 1100 PDT, another leadplane arrived at the fire flown by a pilot receiving a leadplane
pilot check ride who was accompanied by an instructor pilot. This leadplane was to relieve the leadplane
already on the fire, who had been leading airtankers for about three hours.
At the time of the leadplane swap, two of the eight airtankers were on the ground at the Ramona Airport
and the other six were in a single orbit at 6,000 feet MSL east of the fire, loaded and waiting for
instructions. The leadplanes were flying a smaller orbit several miles south and west of the airtanker orbit,
over the area of the fire the airtankers had been working, while one briefed the other. When the relief pilot
was satisfied that he understood the situation, he released the original leadplane to return to the airport.
About three or four minutes later, the relief leadplane, a Forest Service owned and operated Beechcraft
Baron B-58P, received instructions to stop airtanker operations over the fire. All of the airtankers were to
return to base still
loaded. One airtanker was directed to a different airport while the other five, along with
the relief leadplane, were directed to the Ramona Airport. The inbound airtankers turned out of their orbit
one by one as they came around to a westerly heading to the airport, strung out in trail one or two miles
apart. They gradually descended.
As the relief leadplane headed toward the airport, his course converged slightly on the airtanker string’s
course and he noted they were initially about one half mile abeam and to the left of the third airtanker in
line. The relief leadplane pilot radioed the airtanker pilots to caution them that they were all bound for the
airport together and should look out for one another. This transmission was on the air tactical AM 122.925
frequency. All five airtankers acknowledged this transmission.
As the airtankers and relief leadplane proceeded toward the airport, the relief leadplane heard the original
leadplane, also a Forest Service owned Baron, call the ATB for a fuel truck to meet him, first by mistake on
the AM 123.975, the helicopter tactical frequency in use on the fire, then on AM 122.925, the frequency
guarded by the ATB. The relief leadplane radioed the original leadplane on 122.925, indicating that he
would need fuel too, but the original leadplane pilot did not acknowledge that transmission.
Upon reaching a point about eight to ten miles out, and again at two miles out, the airtankers and the
relief
leadplane pilot presumably reported their positions and intentions to land on the airport’s published
Common Traffic Advisory Frequency (CTAF). Witnesses could not confirm that all airtankers and both
leadplanes had made both of these calls.
As the first airtanker in line, a Douglas C-54G, neared the airport at or very near pattern altitude (1,000 feet
AGL/2,400 feet MSL), they radioed on CTAF that they were two miles out on the initial approach.
Somewhere about this time, the crew of this airtanker lowered their flaps to the approach setting, which
may have caused the airtanker to “balloon up” momentarily if the elevator trim had not already been
corrected.
A few seconds later, the relief leadplane pilot, still to the left of the third airtanker about one quarter mile,
and slightly behind and above, noticed a smaller white aircraft in close proximity to the first airtanker. This
smaller white aircraft was somewhat above, to the left of, behind, and on about the same course of that
airtanker. The pilot of the second airtanker in line, following behind the first airtanker by about one mile or
so, did not see this smaller
white aircraft, although he was closer to the first airtanker than the relief
leadplane.
A few seconds after the first airtanker reported two miles out, this “smaller white aircraft” (which was later
identified as the original Baron leadplane), struck the first airtanker’s vertical fin and rudder from above,
converging from the left and in a descent. The collision occurred about 1,000 to 1,500 feet above a large
department store on Main Street, one and one half miles from the airport at
approximately 1108 PDT.
32
The Baron initially broke off part of the airtanker’s vertical fin and rudder, collapsed the rest, and then the
Baron rolled off. The tails of both aircraft separated. The airtanker may have first pitched up but then
pitched down violently and rolled to the left, eventually striking the ground approximately vertically and
about one mile from the end of Runway 27 at Ramona Airport. The Baron rolled inverted and descended
in a flat spin, impacting the ground a little east of the airtanker. The tails of both aircraft fell widely
separated and landed without substantial further damage a few hundred feet east of the impact points of the
two aircraft.
The airtanker impacted the ground next to a residence and close to another, disintegrated, and began to burn
violently. The Baron struck the ground inverted, more or less intact, and began to burn immediately. The
Captain and Copilot of the airtanker and the pilot of the original leadplane were fatally injured on impact.
A teenager in one of the residences and another teenager behind the same building escaped without injury.
The other residence was unoccupied. Both residences and other items on the properties were consumed by
fire. Two post-mishap grass fires were ignited.
The airtanker that had been second in line flew over the mishap site less than 30 seconds later, made an
overhead approach and immediately landed at Ramona. The remaining three airtankers were diverted to an
alternate ATB. All air operations at the Ramona ATB were suspended.
The mishap investigation team researched all available pilot records. They noted that the leadplane pilot
was qualified in the Baron and for the leadplane mission. He had flown 13.8 hours of leadplane duty on
fires during the two previous days and slightly over three hours on the fire the day of the mishap. This
amount of flying, demanding, and stressful mission of a leadplane pilot, while not unusual, could be
expected to produce some degree of cumulative fatigue. The leadplane pilot was wearing his required PPE.
The Captain of the airtanker was qualified and properly approved as a DC-4 initial attack rated airtanker
pilot. He had more than 750 hours as the PIC in the DC-4 and many season’s experience in Southern
California as an airtanker pilot in this
region. The Copilot was qualified and properly approved as a DC-4
airtanker Copilot. She had little experience in the DC-4 or in airtanker operations. They were not wearing
contract required PPE clothing.
Weather was well above VFR minimums; however, existing haze and/or smog could have handicapped
detection of other aircraft in the vicinity of the airport.
This fire had started on June 19
th
, two days before the mishap. Containment was not expected until June
24
th
. Substantial airtanker and other aircraft operations from the airport in support of this fire had been
occurring and were expected to continue. However, the air activity was not considered a “sustained
operation” and consequently an FAA temporary control tower or other aircraft control capability had not
been obtained. The Ramona Airport has a considerable volume of general aviation traffic, including
student pilots and foreign nationalities with limited command of the English language.
Having presumably left the fire three or four minutes before the airtankers, the original leadplane should
have made his approach and landed well ahead of the first airtanker. The reason for this delay could not be
determined. The mishap leadplane was flying an approach to an overhead pattern at the airport at the time
of the collision. He would have been experiencing a heavy cockpit workload just prior to the collision in
watching for conflicting traffic, adjusting speed, configuring his aircraft for the approach, and going
through checklists. Some of these tasks would have diverted him from scanning outside the aircraft.
The mishap airtanker crew was flying an approach to the same overhead pattern to the airport as the
leadplane at the time of the collision. Both aircraft were close to the same altitude, between 1,000 to 1,500
feet AGL, just prior to the collision. The Captain would have been experiencing a heavy cockpit workload
just prior to the collision accomplishing tasks as well as delegating tasks to and closely supervising his
inexperienced Copilot.
33
The overhead pattern for Runway 27, when approaching from the east, required an aircraft to fly over or
parallel to and to the right (north) of the runway in the direction of landing at pattern altitude of 1,000 feet
AGL, then turn left into the standard landing pattern. This pattern was well known to airtanker pilots and
other fire aircraft pilots as they had consistently used it. The overhead pattern at the airport was not a
published procedure or documented by any other means for the benefit of general aviation pilots not
accustomed to operations at the Ramona Airport. All of the airtanker pilots had been briefed in pre-work
meetings to fly the
overhead approach at this airport 500 feet above the 1,000 foot pattern altitude for light
aircraft before descending into the regular left hand pattern as then previously, but no longer, recommended
in the FAA Airman’s Information Manual (AIM).
When the leadplane drew near the airtanker, the airtanker would have been below, ahead of, and to the
leadplane’s right. Consequently, the leadplane pilot, sitting on the left side of the Baron in level flight,
would not have been able to see the airtanker that was first in line. The Baron, approaching as described,
would not have been readily visible to the crew of the first in line airtanker.
The Baron collided with the airtanker from behind, above, to the left, descending, and on a converging
heading, initially striking the airtanker’s vertical fin and rudder with the bottom of the leadplane’s fuselage.
The leadplane may have pitched up and rolled one way or the other immediately before or after initial
contact. Further damage to both aircraft during the brief period of contact resulted in separation of the
aircrafts tails, rendering both aircraft uncontrollable. Ground impacts of both the aircraft were not
survivable.
The Forest Service investigation team determined the cause of this mid-air collision to be the failure of
each pilot to detect each other’s aircraft visually or to react to each other’s position reports in time to
avoid
the collision. Contributing factors cited were: 1) The failure to obtain an FAA portable control tower or
other air traffic control capability at Ramona when substantial fire aircraft operations began, 2) Ordering
five airtankers and a leadplane to return to Ramona from the same fire at the same time, 3) The original
leadplane pilot’s unaccountable delay in returning to Ramona, and 4) The inadequate procedure for pilots
broadcasting position reports on the CTAF with no assurance anyone was hearing them, especially at a
busy uncontrolled field and at a time when a number or aircraft were converging on the same approach to
land.
The NTSB investigation report for this mid-air collision is numbered LAX95GA219A/B.
The wreckage of the leadplane is in the upper left hand corner of this photo, the airtanker near the
center. Burning are the two residences. The tail sections of both aircraft are not pictured here.
Photo by Scott Linnett of the San Diego Union Tribune.
34
June 27, 1998 found the Gila National Forest experiencing fires requiring the services of air resources. A
Neptune P2V-7 (US Navy version Lockheed SP-2H) airtanker was dispatched for extended aerial attack
from the ATB in Albuquerque, New Mexico to the fire complex in the morning hours of that date. The
Captain, flying as the PIC and pilot in control, and the Copilot were the only two people on board.
The airtanker returned to the ATB after two missions on the fire. The airtanker was dispatched again that
same afternoon. The airtanker crew departed the ATB and flew to another fire on the Gila with the Captain
again as the pilot in control. Aerial operations on the fire were under the control of an Air Tactical Group
Supervisor (ATGS) aircraft and a leadplane. The airtanker made one drop on the northwest side of this
fire.
While in flight back to the ATB, the Captain requested permission from the leadplane to allow assuming
the duties of pilot at the controls (left seat) on the remaining mission. Permission was granted and the
change occurred as the airtanker was reloaded with retardant at the ATB.
With the Copilot now in the left seat, the airtanker returned to the fire and dropped retardant on its southern
flank with leadplane assistance and without a dry run. The airtanker then returned to the ATB once more.
During this time, the leadplane departed the fire to begin a rest break, as required by Forest Service
Southwest Region policy.
After reloading, the airtanker, with the Copilot still at the controls and in the left seat, returned to the fire.
Under the supervision of the ATGS, they completed a dry run on the southern flank of the fire, the same
pattern as the previous leadplane assisted the drop run. Due to terrain considerations, a right turn flight
pattern was being used for airtanker drops on the south side of the fire.
The airtanker then began the drop run and began to transition from the base leg to the final leg in a sharp
right bank turn. While in this turn, the right wing struck the top of a Ponderosa Pine tree about 55 feet
above ground level, shearing off a part of the right flap. The airtanker continued at a downward angle with
the right propeller striking a second tree about 45 feet above ground level, shattering the propeller. The
right wing then hit a third tree about eight feet above ground. The airtanker flew into the ground nose
down and in a right bank. During this mishap sequence, the configuration of the airtanker was full flaps,
gear up, with both jet assists at flight idle, and both reciprocating engines running, the normal configuration
for this phase of flight.
Ground firefighting engines and crews were on scene for an immediate attempt to rescue. A small post-
mishap fire began and two airtanker drops were conducted so that the ground crew could work. Both pilots
were fatally injured upon impact.
On April 27, 1998, the date he was issued an Interagency Pilot Approval, the Captain possessed 7,775
hours of total flight time. Broken down into categories, it was determined that on that date he had 7,475
hours as the PIC in all aircraft, 325 hours of these hours were as the PIC in the P2V. 2,960 hours were
logged as the PIC of Airtanker/Dispensing Operations. He was not a Certified Flight Instructor (CFI). He
was Initial Attack qualified and 1998 was the 30
th
year this Captain was carded for fire missions.
On April 27, 1998, the date he was issued an Interagency Pilot Approval, the Copilot possessed 8,337 hours
total flight time. He listed 7,740 hours as the PIC in all aircraft; 291.3 hours of these hours were as the PIC
in the P2V. 17.7 hours were logged as the PIC of “low level” operations (<500 feet AGL). In addition,
17.7 hours were listed as the PIC of Airtanker/Dispensing Operations. He was in training for initial attack
qualifications and 1998 was the 5
th
year this Copilot was carded for fire missions.
Both pilots had the previous day off.
Forest Service policy, at the time of this mishap, did not require flight instruction to be given by a CFI.
The Forest Service had no specific low altitude (500 feet AGL and below) experience requirements for
contract or agency pilots.
35
During the investigation process, the ATGS stated that he observed the airtanker making a descending right
base to final turn that took the airtanker over a set of power lines west of the fire area. This was the same
flight pattern used by the other airtankers. The investigation team determined the stated power line was to
the west of the drop area about .14 miles (756 feet) from the first tree struck during the mishap sequence.
The power line reached 90 feet high.
After the airtanker passed over the power lines, the ATGS observed it continue the descending right turn
and noticed that the airtanker crew did not level the wings. The airtanker’s right wing struck a tree at
approximately 55 feet above the ground, taking off a piece of the right wing flap.
Weather in the area consisted of winds out of the southwest at five to ten mph, and according to witness
accounts, visibility was not a factor. Official sunset was at 2024 MDT, the same time the mishap occurred.
The general terrain in the drop area was slightly descending and the terrain around the drop area had rising
terrain to the northwest. The Ponderosa Pine forest canopy was generally uniform at a height of about 60
feet.
The investigation team discovered that the airtanker was scheduled to return to their original ATB at the
end of this last mission, but that the airtanker crew would not have had sufficient fuel to get there.
The post-mishap toxicological report for the pilot flying the airtanker at the time of the mishap, the Copilot,
revealed a presence of two antihistamines, Brompheniramine and Chlorpheniramine. At any detectable
tissue level, the most common adverse reactions of these medications may include drowsiness, sedation,
dizziness, faintness, and disturbed coordination.
The probable cause of this mishap was stated as: While in a right bank descending turn, the right wing
struck the top of a Ponderosa Pine tree. Contributing factors included: 1) The toxicological report for the
pilot flying the airtanker revealed a presence of Brompheniramine and Chlorpheniramine, both
antihistamines. At any detectable tissue level, the most common adverse reactions of these medications
may include drowsiness, sedation, dizziness, faintness, and disturbed coordination, 2) The pilot flying was
inexperienced in low level flight, and 3) The airtanker was in too steep of a turn and at too low of an
airspeed to maintain altitude. The airtanker struck trees resulting in a loss of control of the airtanker.
Main wreckage location of the Neptune P2V-7, Navy version Lockheed SP-2H.
36
This C-130A aircraft, on contract to the Forest Service, was manufactured in 1957 by Lockheed and placed
into service for the US Air Force in 1957.
In 1988, the aircraft became a civilian asset operated by a Forest Service contractor and was put into
service as an airtanker.
On June 17, 2002 at about 1429 MDT, this C-130A airtanker took off from the Minden, Nevada ATB to
drop retardant on a fire burning on the Humboldt-Toiyabe National Forest.
A company flight plan had been filed for this mission, which took place in VMC.
At about 1445 PDT, the airtanker had initiated a retardant delivery run. During the delivery, the airtanker
experienced an in-flight structural failure as its wings separated from the fuselage near the wing roots. As a
result, the remaining fuselage collided with terrain.
A fire ignited on the ground in the area of the separated wings. An additional fire ignited on the ground by
the remaining airtanker debris. The mishap location was adjacent to the small community of Walker,
California. The fires were quickly suppressed before spreading into the community
.
The Captain, Copilot, and Flight Engineer were fatally injured.
A videotape of the mishap sequence filmed by an on scene news reporter aided the mishap investigation
teams from the NTSB and Forest Service.
Recorded winds at the Reno-Tahoe Airport, located about 30 miles northwest of the mishap site, were 190
degrees at 15 knots with gusts to 21 knots.
Examination of the airtanker maintenance records indicated that the airtanker had a total of 21,747.91 flight
hours at the time of the mishap.
The investigation process was ongoing at the time this booklet was written. The NTSB file number for this
mishap is LAX02GA201.
37
C-130A airtanker as its wings separated from the fuselage near the wing roots.
C-130A airtanker after its wings separated from the fuselage.
Photos taken from videotape filmed by KOLO-TV, Reno, Nevada.
38
On July 18, 2002, three airtankers, a helicopter, and a leadplane were dispatched to a fire burning in the
Arapahoe/Roosevelt National Forest, not far from Estes Park, Colorado. One of the airtankers was a 57-
year-old Consolidated Vultee PB4Y-2 Privateer procured by the Forest Service on a contract. The PB4Y-2
had flown seven previous missions on this fire the same day.
The PB4Y-2 airtanker was loaded with approximately 2,000 gallons of fire retardant and 550 gallons of
fuel. At 1815 MDT, the PB4Y-2 departed the ATB at Broomfield, Colorado and joined up with the
leadplane on a retardant run as another airtanker observed from behind and above. The pilots of the second
airtanker observed “the left wing tip” of the PB4Y-2 “coming up,” “there was some asymmetry of the
airplane.” The left wing separated from the airtanker near the fuselage and airtanker control was lost.
Shortly after wing separation, fire erupted at the fuselage/wing separation point. The fire continued to burn
and upon impact with the ground, ignited a spot fire.
The post mishap fire partially consumed portions of the wreckage. The spot fire was contained the same
day. The mishap was located in mountainous terrain six miles southwest of Estes Park, Colorado. The
PB4Y-2 was destroyed.
Both pilots of the PB4Y-2 airtanker were fatally injured.
An amateur photographer captured several digital photos of the mishap sequence, which aided the NTSB
and Forest Service mishap investigators.
The Captain of the second airtanker said, (sic) the third airtanker had just completed his drop “and (PB4Y-
2) had observed the drop and was preparing to drop. All communication between (PB4Y-2) and (the
leadplane) was normal. I fell behind (the PB4Y-2) on downwind and base. I looked away momentarily
and I again focused on (the PB4Y-2). I noticed his left wing was falling. The aircraft was in a 15 to 20
degree bank. I next saw fire near the fuselage as the wing failed inboard of the number two engine. The
aircraft pitched nose down in a huge fireball and plunged into the ground vertically starting an immediate
large fire.”
The Copilot of the second airtanker said this airtanker was in his base turn for the drop and in a “smooth 15
to 20-degree bank turn,” when the left wing separated from the airtanker. “The aircraft then went into a
rotation and impacted the ground.” This Copilot said that operations were normal and the weather in the
area consisted of “the smoothest,
least turbulent conditions of the day.”
The leadplane pilot stated that the conditions were perfect for a tanker drop. There was no turbulence and
no smoke in that area. He had been working with the third airtanker and then instructed the
PB4Y-2 that
they would be extending the drop just made. The PB4Y-2 responded to the positive and said that he was on
downwind for the drop. The leadplane pilot told him that he was at his eight o’clock and the airtanker pilot
stated he had him in sight.
The leadplane pilot then told the PB4Y-2 pilot that he would come up on his left side and continue
downwind with him until he was ready to turn back. The airtanker pilot responded, “I think I’m going to
use this nice big valley to turn around in.” The leadplane pilot told him that sounded like a good idea.
They flew approximately 15 seconds before the airtanker began a gentle turn to final. They continued in
the turn from downwind to final without squaring off for a base, which is normal on airtanker runs.
The leadplane pilot said that after he turned on final, he told the Captain of the PB4Y-2 that his attack run
would require a pitch over which was approximately one half mile ahead. The leadplane pilot said after he
finished that transmission, the Captain of the second airtanker called him and said that the left wing had just
come off of the PB4Y-2 and the airplane had gone in.
Weather and terrain did not appear to be factors in the mishap.
39
The investigation process was ongoing at the time this booklet was written. The NTSB file number for this
mishap is DEN02GA074.
PB4Y-2 airtanker upon wing separation.
Photo taken by amateur photographer, name unknown.
PB4Y-2 main wreckage.
40
PB4Y-2 separated left wing.
41
LEARNING
EXPERIENCES
Section Two
FATAL
HELICOPTER
MISHAPS
42
This mishap occurred in the Stikine Area of the Tongass National Forest in the Alaska Region. The United
States Department of Agriculture Forest Service exclusive-use Bell 47-G3B-1 was being utilized at a spike
camp for project crew transportation.
The helicopter was available July 16, 1976 and was dispatched from Petersburg to Big John Bay to deliver
mail and move crews. This was completed and the helicopter then went to Rowan Bay on Kuiu Island to
remain overnight. On Saturday the 17
th
, the helicopter was used to move crews to remote work sites in the
morning and returned them in the afternoon to the Rowan Bay Camp.
At about 1715 hours Alaska Daylight Time (ADT), July 17
th
, the helicopter departed from the Rowan Bay
Camp headed for the Big John Bay Camp with a final destination of Petersburg. A Forest Service
employee was on board, desiring to go to Petersburg on his day off. At about 1730 ADT, the helicopter
landed at the Big John Bay Camp, the pilot loaded two empty propane bottles onto the external racks, and
secured the bottles with a bungee cord. At about 1750 ADT, the helicopter again took off with one
passenger enroute to Petersburg. At a point five miles from Petersburg in Duncan Pass, the helicopter
encountered the mishap.
The helicopter was not missed until Monday, July 19
th
, when it could not be located for work. A search
was then initiated and the wreckage was located. According to a stopped watch found at the
wreckage
location, the estimated time of the mishap was 1804 ADT, July 17
th
.
Upon investigation of the wreckage, it was determined that initial impact into a large snag occurred about
25 feet above the ground. However, there was lack of tree and branch breakage near the major wreckage.
The helicopter was believed to be on a true course of 095 degrees at the point of impact. After contacting
the snag, the helicopter slid down it, scarring it heavily, and came to rest inverted at its base. A fire
erupted, burning the cockpit and engine areas. The main rotor mast was broken and the main rotor was
separated from the helicopter. The broken piece of mast was not found. The tail rotor blades were
separated from the gearbox and the tail rotor gearbox was separated from the helicopter. The tail rotor
blade was found 411 feet from the fuselage of the helicopter.
The pilot and passenger died instantly of injuries sustained in the mishap.
Dispatching of this helicopter was conducted from Petersburg, but flight following was done by the Rowan
Bay Camp Cook. While at Rowan Bay, the helicopter’s movements were monitored closely by
Rowan
Bay and loosely by the Dispatcher in Petersburg. Past policy had been for the pilot to check in with the
Petersburg Dispatcher upon arrival at the airport and not with Rowan Bay.
The Emergency Locator Transmitter (ELT) was activated and appeared to be operating normally. No
aircraft in the area had been monitoring 121.5, the frequency to detect the ELT signal.
The Forest Service National Helicopter Manager inspected both the helicopter and pilot on May 17, 1976.
The pilot received a Forest Service Pilot Card that day.
The pilot had accumulated 3,500 hours total flight time, 400 hours in make and model, 150 hours in last 60
days, and 550 hours mountain flying time prior to the day of his initial inspection.
The pilot had flown a total of 4.2 hours the day of the mishap and had been on duty for 11 hours. He spent
between 1330 ADT and 1445 ADT taking a nap at the Rowan Bay Camp.
Deficiencies were found on the helicopter during its inspection on May 17, 1976. These deficiencies were
soon corrected and the helicopter became available under the contract on May 23, 1976. The helicopter
had been unavailable on June 7, 1976 because of an inoperative generator. It was again unavailable July 7
th
and 8
th
because of an inoperative magneto. Between July 9
th
and 13
th
it had been unavailable while waiting
for a main rotor blade replacement. It was again unavailable July 14
th
and 15
th
because of a supercharger
problem.
43
The tail rotor blade had a mandatory change time of 600 hours. At the time of the mishap, the blades had
been installed on this helicopter for a total of 622 hours.
Weather at the time of the mishap was estimated at 1,500 feet overcast, better than five miles visibility, and
gusty winds to 20 knots from the south. There were rain showers of varying intensity in the area.
Further analysis of tail rotor blade Serial #A-376016 A-376008, which had been found 411 feet from the
fuselage of the helicopter, revealed that this blade had a separation fracture at the grip area. Initial National
Transportation Safety Board (NTSB) reports indicated that the separation was caused by fatigue failure of
the tail rotor blade material. This caused severe vibration, separating the tail rotor gearbox and remaining
blade from the helicopter. This then caused the loss of control of the helicopter, which resulted in the
mishap.
Bell 47-G3B-1 wreckage.
Black and white photo.
44
The evening of July 24, 1977 was clear with half-moon light conditions. The temperature was 70 degrees
Fahrenheit. Night helicopter operations were taking place on the fire burning in the Angeles National
Forest in southern California. The terrain was mountainous and the helispot elevation was 5,000 feet.
Three helicopters were operating with pilots using Night Vision Goggles (NVG) from the Mill Creek
Heliport. The local County Fire Department (County FD) was operating their Bell 205 A-1 and the Forest
Service was using two contract helicopters.
An unscheduled night briefing for helicopter operations began at approximately 2040 hours Pacific
Daylight Time (PDT) at the helibase. The Forest Service contract helicopter pilots attended this briefing.
The County FD helicopter pilots did not attend, but the Fire Department Air Officer did. This discussion
included the location of potential hazards (power lines, telephone lines, etc.), the size of the helibase, the
need for separation of helicopters, and landing and takeoff procedures. These procedures could be
summarized to say that one helicopter was to land at a time and that the pilots would be responsible for
spacing the helicopters.
It was at this briefing that the South Zone Helicopter Specialist expressed concern that the helibase would
be marginal for operating all three helicopters scheduled to be on the night mission. The Forest Liaison
with the County FD was contacted and informed that only two helicopters would work out of the helibase.
The liaison indicated the County FD helicopter would operate from an alternate helibase.
It was at this time the County FD Air Officer arrived at the briefing and discussed possible hazards. A
discussion ensued between the County FD Air Officer and the South Zone Air Unit Helicopter Program
Management Officer concerning the feasibility of working all three helicopters at the one helibase. It was
then decided to work the two Forest Service contract helicopters and the County FD helicopter out of the
same helibase.
The primary reason for not operating the County FD helicopter out of the alternate helibase was inadequate
water supply. Procedures were discussed for placement of helicopters and service vehicles. At 2137 PDT,
the County FD Air Officer briefed the County FD pilots on the procedures and other points brought out
during the briefing and subsequent discussion. This briefing took place over the radio in one minute and 15
seconds.
Night water dropping operations commenced at 2155 PDT. The two Forest Service contract
helicopters
were first and second to lift-off. All of the pilots experienced difficulty contacting ground forces to receive
directions for priority water-drop targets.
At 2200 PDT, the County FD helicopter lifted off the helibase to go on a drop run. A short time later, the
County FD helicopter returned and entered what witnesses described as a normal downwind traffic pattern
at an estimated three quarters of a mile west of the heliport. The Forest Service contract Bell 212 returned
from its fourth water drop and entered a downwind traffic pattern over the highway.
Both pilots in the Forest Service Bell 212 stated they saw the County FD helicopter approximately one half
mile ahead and outside of their traffic pattern on downwind to the helispot. The Forest Service pilot stated
that the County FD pilot was making an approach that was steeper than his own previous three approaches.
The Forest Service pilots stated they called turning final over the traffic frequency and that they heard the
County FD pilot call turning final. It is not known if the County FD pilots heard the Forest Service pilots
call final.
Ground witnesses observed the County FD helicopter during its downwind, base, and final legs during their
approach. However, relative positions of both helicopters at the time of impact and witness statements
substantiate that the County FD helicopter was making a shallow to normal approach of approximately 15
to 20 degrees.
45
A mid-air collision occurred on final approach, approximately 75 yards from the Mill Creek Heliport. The
time was about 2230 PDT.
The Forest Service pilot stated the first hit was loud, but felt light. The second hit was much louder. He
described the impact like something gnawing in the rear. He said his helicopter pitched nose down and
started spinning to the right. He estimated the helicopter turned a full 360 degrees and an additional 180
degrees before the first ground impact.
The Forest Service pilot chopped the throttles after the full 360-degree turn and lowered the collective. He
managed to hold a flat pitch attitude in spite of an estimated 45-degree nose low position. The helicopter
leveled somewhat, still spinning, and impacted the ground at the heliport in a slightly nose low attitude. It
bounced about 10 to 12 feet and came to rest on a heading of 010 degrees.
The exact impact point of the County FD helicopter on the ground could not be established. Traces of
impact evidence were destroyed as rescue activity kicked up the dirt. The helicopter probably hit the
ground and bounced downhill approximately ten feet, coming to rest in a left tilted upright position. The
engine continued to run in spite of rescue personnel’s efforts to shut it down. Estimates of time indicated it
was 40 to 45 minutes before the engine finally quit from fuel starvation.
There were a number of individuals involved in this mid-air collision.
There were two pilots in each helicopter.
In March of 1977, County Fire Department Pilot #1 had 8,300 hours total flight time, 4,800 plus hours in
the Bell 204/205/206. In April of 1977, County Fire Department Pilot #2 had 7,155 hours total flight time,
5,000 hours in the Bell 204B/205A-1. County FD Pilot #2 was approved by the Forest Service as a check
pilot for NVG training. It was undetermined which County FD pilot was actually flying the Bell 205. One
of these pilots was critically injured and the other was fatally injured. The deceased pilot had made a
daylight reconnaissance flight, the injured pilot had not. Both pilots in the County FD helicopter made a
night reconnaissance flight prior to their first landing.
The Forest Service contract pilots in the Bell 212 sustained very minor injuries. Forest Service Pilot #1 had
4,500 hours total flight time, 250 of which were in this make and model. He had been approved for night
vision missions on July 1, 1977. Forest Service Pilot #2 had 4,700 hours total flight time, 550 of which
were in this make and model. He was approved for night vision missions on June 17, 1977.
Three of the four pilots’ helmets came off during the course of the mishap. All four pilots were qualified
and current for NVG operations.
Sometime before entering the traffic pattern, the County FD pilots radioed the Forest Service
contract Bell
212 pilots stating they would like to follow them on the next water drop. Because of this, the Bell 212
pilots understood the County FD pilots intended to follow the Bell 212 to land. The County FD helicopter
was making a wider traffic pattern than the Forest Service contract helicopter. The Forest Service pilot’s
last visual contact of the County FD helicopter was as the Forest Service Bell 212 was turning base leg. At
that time, he estimated the County FD helicopter’s position to be one half mile to the left of his own
helicopter at approximately the same altitude and generally eastbound.
Three witnesses stated that on final approach, both helicopters were descending; the upper helicopter
(Forest Service) was descending more steeply than the other one (County FD). The two helicopters came
together in this relative position.
Ground personnel could not visually distinguish one helicopter from another in flight after dark.
Nonetheless, witnesses stated that County FD pilots had been consistently making standard landing patterns
terminating in final approaches described as shallow to normal. The last landing pattern flown by the
Forest Service mishap contract helicopter was slightly different than previous ones in that their downwind
46
leg was about 200 feet higher and the final approach was a steep one. The Forest Service mishap pilots
expressed concern about power lines in the vicinity of the landing pattern and gave this as the reason for
their steep final approaches. This approach was not found to be outside of safety limits.
The fire command system was undergoing a shift change from a Class II to a Class I fire team at the time of
the mishap. The night operations briefing was not conducted in accordance with the Helicopter Night
Flying Operations Guidelines.
The mishap investigation revealed that navigation lights on all three helicopters were observed “on” during
the night operation. It was found that air traffic separation and sequencing procedures were not clearly
defined. The South Zone Forest Service Helicopter Management Officer had reservations about the
procedures of flying three helicopters out of one helibase at night. The Helicopter Manager and the County
FD Air Officer agreed it was feasible to operate three helicopters out of the helibase that night. Neither of
these two personnel were a part of the formal Forest Service organization at the time. Their agreement to
fly three helicopters out of the one helibase was accepted and implemented by the Helibase Manager,
whose authority it was to authorize such activity.
Both Forest Service Forest and Air Net frequencies were overloaded with radio traffic. This interfered with
communications between helicopters and the helibase. Because of the problems in making radio contact
with personnel on the fire lines, the pilots and the Helibase Manager could not determine the locations for
priority water drops.
The Helibase Manager had been contemplating shutting down air operations until effective
communications could be established with ground forces. The County FD helicopter did not have Forest
Service Forest Net capabilities. During the fatal landing pattern, helibase personnel did not hear either the
Forest Service or County FD helicopters announce turning final on the Air Net frequency. Prior to this, all
incoming helicopters had been heard to make that report on Air Net. Both helicopters were operating on
aircraft VHF frequency 118.95. After the mishap, the transmitter selector switches on both helicopters
were found to be in that position.
There were at least two pairs of signal wands in use on the helibase. A Forest Service employee gave
County FD ground personnel a pair of wands though they had not specifically requested them.
These
second pair of wands was obtained without approval of the Helibase Manager. The Deck Manager knew
County FD personnel had them.
Under Forest Service procedures, it is the Deck Manager’s job to assign pads for arriving aircraft. By the
Deck Manager’s testimony, on at least one occasion, the County FD pilots had landed on the north pad
even though he had been signaled to land on the south pad. It was the understanding of the County FD Air
Officer that the north pad was the only one to be used for water filling. It was
impossible for the Deck
Manager to visually identify any one helicopter from the others in the dark. The Deck Manager’s authority
and responsibilities were not clearly understood in regard to the County FD helicopter pilots and ground
crew.
The Helicopter Night Flying Operations Guidelines had not been adopted as mandatory by either agency.
As a result, the briefing did not include all pilots or all ground personnel. Crash/rescue procedures were
not discussed. The Air Traffic Boss position was not filled as called for in a multi-aircraft night operation.
Check points were not assigned to assure air traffic separation. Uniform flight patterns had not been
established.
There was not a formal agreement between the two agencies, the Forest Service and County FD, regarding
operational procedures for fire suppression.
No evidence was found of mechanical failure in either helicopter. There was no evidence of NVG failure.
All NVGs were examined and determined that the objective lenses were all on “infinity” setting, as
opposed to close-up for instrument viewing.
47
The investigation team concluded that the County FD helicopter did not see the Forest Service mishap
helicopter during their final approach. This was considered probable because of limited 40-degree vision
when wearing night vision goggles.
Forest Service contract helicopter on helibase, post-mishap.
Final resting place of the County Fire Department helicopter (near center of photo) in relation to the
helibase and to the Forest Service contract helicopter (in top right hand corner) post-mishap.
Photos in black and white.
48
In the Alaska Region, a Hiller Model 12J3 (Soloy Turbine conversion of Hiller 12E) was being used to
support a Forest Service survey crew on Prince of Wales Island on the Ketchikan Area of the Tongass
National Forest.
On July 28, 1977, the day of the mishap, the helicopter did not fly in the morning due to low weather
conditions. At 1030 ADT, a five-person crew had hiked into the work site. The weather improved in the
afternoon, which permitted flight to begin.
At 1707 ADT, the helicopter left the spike camp for the first of three flights to pick up the survey crew. On
the second pickup and return to the spike camp, the helicopter went out of control and impacted terrain
2,690 feet from the point of takeoff. The angle of descent prior to impact was relatively steep
(approximately 45 to 55 degrees) as indicated by tree strikes. After impact with the ground, the helicopter
pivoted forward and over, and came to rest in an inverted nose low attitude. The passenger, who was
seated in the right seat, was killed instantly. The center seat passenger was seriously injured. The pilot
sustained head injuries and suffered from shock and loss of memory.
The mishap occurred at about 1715 ADT. The helicopter was being flight followed at the time. Search and
rescue procedures were initiated promptly and another helicopter arrived over the mishap site at 1745 ADT.
Additional personnel and a doctor were dispatched to the mishap site and the victims were subsequently
evacuated to Ketchikan.
The weather was estimated as 1,500 feet broken clouds with 20 miles visibility and light winds. The
weather reported at the Ketchikan Airport (approximately 35 miles away) during the same period was a
ceiling of 2,000 feet, winds at 11 knots, temperature at 58 degrees Fahrenheit and dew point at 53 degrees
Fahrenheit.
The investigation of the mishap revealed that the helicopter was being operated within all Federal Aviation
Administration (FAA) and Forest Service guidelines. All maintenance inspections were current. All
applicable Airworthiness Directives were current and complied with. All time limited components were
within prescribed limits. The helicopter was within its allowable gross weight and had adequate fuel on
board.
At the time of his Forest Service Inspection on April 21, 1977, the pilot had a total Pilot in Command (PIC)
time of 1,445.2 hours. His time in the Hiller Model 12J3 was 290.3 hours. He had flown only .4 hours in
the last 60 days.
The engine, fuel control, and governor were disassembled for further investigation. There were no unusual
results discovered. All systems were
inspected at the mishap scene. The only apparent failure of a
component, not thought to be impact related, was of the cyclic control isolation link. The rod end of this
isolation link that attached to the cyclic control bell cranks, which are mounted to the transmission,
appeared to have fatigue failure. This was later confirmed by microscopic examination at the NTSB
laboratory. A failure of this type would have most probably resulted in loss of cyclic control.
49
Hiller Model 12J3 wreckage.
Black and white photographs.
50
The Selway Ranger District in the Nez Perce National Forest in Idaho (Intermountain Region) were using a
contract Bell 206BIII to conduct helitorch operations on August 22, 1984.
There were a number of Forest Service employees taking part in the helitorch job:
The Helitack Foreman on site began employment with the Forest Service in 1973 and began working with
helicopters in 1975. He had intermittent experience with the helitorch beginning in 1979. His most recent
helitorch experience was in April and May of 1984. He was qualified as the Division Boss, Air Service
Manager – Heliport I, and Tanker Boss.
The Assistant Helitack Foreman had eight years in the Forest Service, all served on the Nez Perce. His
training record indicated he was well versed in Forest Service helicopter activities. He had received
helitorch training in 1979, and was involved in several helitorch wildlife burn projects from 1979 through
1984. He was continuing his qualifications to operate the helitorch. He was qualified as Air
Service Manager – Heliport I and Sector Boss.
The Forest Service had seasonally employed the Helitack Crew Member acting as the Marshaller since
1974, working a variety of Forest Service fire and aviation jobs. He had several seasons as a crewmember
on a helitack crew, but only one day of previous helitorch operating experience. He had never marshaled a
helitorch operation prior to the day of the mishap. He had marshaled on other projects with the pilot and
helicopter being used on this day.
The Forest had obtained a Technical Advisor for this project. This Supervisory Forestry Technician began
working for the Forest Service in 1965. He encompassed a wide background in fire and aviation
management and had accumulated a lot of experience with helitorch operations. He guided the set-up of
the heliport and worked with the rest of the crew on repairing and making sure the helitorches were
working properly.
The contractor’s pilot was properly carded for the Bell 206B. He was approved for: reconnaissance, fire
suppression, sling loads, animal counting, snow landings, rescue, helitorch, and long line missions. He had
accumulated 1,000 hours in Bell 206A and Bell 206B helicopters. He stated he was first approved for
helitorch flying in 1980. He had read a lot of information concerning helitorch flying and had discussed its
handling and operations with many people. His first actual helitorch flight took place August 21, 1984.
On August 21, 1984, eight barrels of jellied gasoline were flown using one of two torches located at the
Round Top Mountain Heliport. The pilot experienced numerous problems with intermittent ignition or
pumping with the torch. In
addition, the support crew experienced three or four cable entanglements on
this day and began placing a person at the torch to alleviate these cable entanglements.
The heliport was located on an east-west running ridgeline covered with grass and widely scattered trees
and brush. The grass provided excellent dust abatement and there were no trees or brush within 100 to 125
feet of the mishap site. Approach and departure routes were available throughout 360 degrees.
While the helicopter was flying with this first torch, the crew was maintaining the second helitorch. They
tightened up loose electric connections and determined that the cables were of proper length, the same as
the first helitorch. Because the jelling time of the mix was taking so long, the crew decided to pre-mix four
extra barrels so that they would be properly jelled in time for use.
On the morning of August 22
nd
, the second helitorch was placed perpendicular to the landing pad at the
heliport; it was to be the active helitorch this day. The four pre-mixed barrels were placed beside the active
helitorch and the inactive helitorch was located beside the last barrel in the row of four. Locating the extra
barrels so close to the operating area was to minimize the amount of time and effort needed to replenish the
torch. A decision was made to keep the Assistant Helitack Foreman close to the active helitorch during its
lift-off to alleviate any cable entanglements.
51
At 1117 PDT, the helitorch suspension cables became entangled about the torch itself. The Assistant
Foreman was correcting the entanglement when the helicopter started a right hand spin while hovering over
the helitorch. The Assistant Foreman attempted to move away. The helicopter spun approximately 180
degrees. The tail rotor fatally struck the Assistant Foreman.
When the strike occurred, the Marshaller was approximately 20 feet in front of the helicopter. The Helitack
Foreman and the Technical Advisor were standing behind a one and a half ton stake truck, watching
activities through the windshield of the truck.
During investigation interviews, the Technical Advisor explained that he had always placed the drip torch
at the side of the helicopter so the pilot could observe it easier through the pilot’s door. This was opposed
to putting it in front of the helicopter, requiring the pilot to observe it through the chin bubble. He stated
that on prior jobs the only time it had been put in front of the helicopter in this Region was when a Hughes
500 was utilized for the job. He stated that cable entanglements were a very common occurrence and he
felt that the cables would become entangled whether the torch was placed in front or to the side of the
helicopter.
In his mind, the pilot had questioned the reason for putting the helitorch to the side of the helicopter instead
of the front. He did not ask anyone present about his concern because he thought they all had plentiful
helitorch experience.
Further investigation showed that the pilot, helicopter, and crew had not trained as a unit with the mishap
helitorch. The Regional Helicopter Program Officer had made efforts on several occasions to get the torch,
pilot, helicopter, and crew together to accomplish training, but these efforts failed because of the inability
to get the helitorch to the same location as the crew. The helitorch was funded out of another District and
was stored there until it was requested for use.
The helitorch wiring did not meet contract specifications due to helicopter circuit breaker problems.
Auxiliary wiring was installed. This wiring was connected to the primary buss in the battery box, through a
switch mounted on the cyclic control, to a circuit breaker, then out to the cargo hook. This wiring was
taped to the fuselage exterior and to the cyclic with duct tape. The helicopter met all other contract
specifications.
An overall operations and safety briefing was conducted and attended by all personnel involved in this
project on the morning of August 21
st
. A helicopter helitorch specific safety briefing was conducted at the
heliport just prior to actual operations on August 21
st
.
Reportedly, the primary cause of this mishap was that the helitorch cables became entangled about itself.
The asymmetric center of gravity which caused the helicopter to roll right and yaw right would not have
occurred if the cables had not become entangled as they did.
There were several contributing factors that added to the severity of this mishap: 1) The fatally injured
Assistant Foreman was underneath the helicopter and moving about the helitorch attempting to untangle the
cables before the helicopter was in a stable hover, 2) There were extra barrels of jellied gasoline and other
miscellaneous equipment in the immediate operating area. They provided stumbling blocks for the
Assistant Foreman during his attempt to escape the area and provided a psychological deterrent to the pilot,
3) Communications, visual and verbal, between the pilot and signalman, were inadequate. The pilot could
not fully assess the extent of cable tangles, and 4) Placing the helitroch at the side of and perpendicular to
the helicopter promoted the probability of a cable entanglement because of the multiple movements
required to get the helicopter centered over the helitorch, particularly in gusting wind conditions.
52
Bell 206BIII post-mishap photograph.
53
A properly carded Forest Service contracted Aerospatiale Alouette III (SA316B) was working on fire
missions in the Pacific Northwest Region. More specifically, the helicopter and the pilot (who was the sole
occupant of the helicopter) were in the Okanogan National Forest, just west of Winthrope, Washington.
On August 8, 1985, a Safecom had been submitted pertaining to this helicopter and the loss of the longline
hook. The crew wrote that neither they nor the pilot could explain how it could have happened.
On August 9, 1985, this helicopter departed North Cascades Smokejumper Base (NCSB) with a longline
load, external basket cargo, and internal cargo and flew to Helispot 1 (H-1). He landed and some cargo
was off-loaded. Some other cargo was taken out of the baskets and put into the cargo net.
The helicopter then departed H-1 for the fire line with a longline external load in support of fire activities.
Over the radio, the pilot advised the ground person that they would need to physically disconnect the load
because there was no remote hook. The load was successfully placed on the ground. The external load
delivered was well within the aircraft’s weight-carrying ability.
The helicopter then departed the fire line and flew past H-1 to return to NCSB. The helicopter had a 100
foot 3/8 inch diameter un-weighted steel cable weighing just over 25 pounds (the longline) attached to the
cargo hook at this time. Personnel on H-1 observed the helicopter, passing in an easterly direction abeam
H-1, descending down drainage. They observed the helicopter to be flying faster than normal for an empty
longline and the cable was trailing perhaps 80 degrees back from vertical. They heard unusual noises
shortly after the helicopter passed from their view. The noise was estimated to last four to seven seconds.
It was reported that the helicopter was on fire prior to ground impact. There was no success when radio
contact with the helicopter was attempted. Personnel at H-1 and other observers spotted smoke. Another
helicopter was diverted from dropping water on the fire line to the new smoke, where he made one drop.
This helicopter then flew to H-1, picked up two helitack crewmembers and flew back to the smoke, where
spotting the wreckage of the helicopter confirmed the mishap. The pilot was fatally injured in the mishap.
The terrain consisted of a canyon bottom at 4,000 feet, 30 percent down slope. The area was mountainous
and wooded. It was an overcast day with little wind, 74 degrees Fahrenheit. Weather was not a factor in
the mishap.
The investigation revealed that the pilot was properly carded for Forest Service missions on May 28, 1985.
He did not, however, meet Forest Service contract requirements for flight experience in make, model, and
series at the time of initial carding. He possessed 8,900 hours total flight time, 872 total hours as the PIC,
75 hours as the PIC in this make and model of helicopter, and 75 hours as the PIC in make and model in
this typical terrain.
At the time of this mishap, the Forest Service Helicopter Operations Handbook did not specifically address
longline operations without a remote hook. It did, however, state “The general requirements for the remote
hook guard requirements for the remote hook guard are to: …(4) provide adequate weight to ensure good
flight handling of the remote hook and lead line.”
The FAA approved the company’s Rotorcraft Load Combination Flight Manual for class A, B, and C Load
Combinations on May 20, 1983. It stated in Section II under Airspeed Limitations: (a) Airspeed will be
governed by the flight characteristics of the load and each load which differs substantially from any the
pilot has previously carried will be tested for hovering, slow flight, and maximum airspeed characteristics,
in that order.
The 100-foot longline weighed just over 25 pounds and carried no weight on the bottom end at the time of
the mishap.
54
It was determined that on June 13, 1985 the engine had 887 hours since overhaul. This determination was
based on an overhaul on December 12, 1977. Power checks were exceeding Forest Service requirements of
ten hours between checks.
The investigative engine tear down analysis took place on September 12, 1985. It revealed strong evidence
that an engine failure occurred prior to the helicopter entering the trees.
The investigation team determined the helicopter began to shed parts 750 feet prior to impacting the
ground. The longline cable became entangled in the tail rotor and main rotor systems ultimately causing
the helicopter to collide with the terrain.
The investigation team believed the probable cause of this mishap was an engine failure. It was also
deemed probable the pilot was flying too fast with an unweighted cable at the time of engine failure and the
subsequent maneuvering caused the cable entanglement with the rotor systems. The loss of the tail rotor
system may have contributed to the severity of the mishap.
SA316B engine wreckage.
Tail rotor system with entangled cable was found 250 feet south of the main wreckage. All 100 feet of
the cable was intact and found at this point.
55
On March 6, 1987, the Forest Service was using a chartered Bell 206BII Jet Ranger in the Alaska Region
to transport a project work crew of three.
The Chatham Area Tongass National Forest, Forest Aviation Officer (FAO) was at the airport to see the
flight off. He secured the equipment and passengers, checked the doors were securely closed, and then
cleared the pilot to start the helicopter. A formal safety briefing was not given; apparently because the
individuals had flown many helicopter flights as passengers and knew the procedures.
All three Forest Service passengers were wearing white SPH-4 flight helmets and green Nomex flight suits.
The pilot was wearing a headset, shirt, and Levi trousers. Each person was wearing a jacket. Though a
personal inflatable flotation device was available for each individual, no one had donned one.
The helicopter departed the airport at 0922 hours Alaska Standard Time (AST) and headed for a work site
in Freshwater Bay on Chichagof Island. The FAO returned to the dispatch office to monitor the radio and
flight follow the helicopter. The pilot called with a radio check-in and the FAO responded with an “off”
time of 0922 AST.
Regular radio communications took place between the FAO and the pilot throughout the morning and mid-
afternoon. At 1130 AST, the helicopter was reported to be in the Kennel Creek Area and at 1226 AST the
helicopter reported to be operating in the Freshwater Bay Area. The pilot stated that he had fueled up the
helicopter at the Kennel Creek fuel tank. The pilot had added 15 gallons there, bringing his total fuel on
board to 49 gallons. The helicopter was left running at low revolutions per minute (rpm) during the
refueling.
The helicopter flew through to Peril Strait following the Kadashan Drainage. At 1310 AST, the pilot
checked in at False Island and requested a flight plan extension to 1400 AST, as they would need to follow
the water route to Sitka due to weather. They proceeded across the strait, watching for the opposite
shoreline (about three miles). They reached the shore near the peninsula and followed the shoreline
northeast. One passenger was very familiar with the land features and constantly updated everyone about
their exact location. No one on board seemed concerned about their situation in spite of the reduced
visibility from snow and fog and the low 200 to 500 foot ceilings. Winds were northerly at 20 to 30 knots.
At Sergius Narrows, the helicopter crossed from the north shore of Baranof Island to the south shore of
Chichagof Island. The passenger who was sitting in the left front seat had been monitoring the fuel
quantity; they had 15 gallons (36 minutes) of fuel remaining at this point. The airport was 25 to 27 miles
away.
While crossing Sergius Narrows at 175 to 200 feet above the water and without warning, the engine quit.
The pilot immediately entered an autorotation and attempted to restart the engine. The auto ignition system
was inoperative and turned off. The pilot had determined this during his preflight. A right turn of
approximately 150 degrees toward an island was made and the airspeed was reduced to 10 to 20 miles per
hour (mph) before impacting the water northwest of Rapids Island. The pilot and two of the passengers
saw the red engine-out light and a yellow low-rotor-rpm light on the annunciator panel.
Impact with the water was very hard, nose high, and in a right bank (approximately 10 degrees) attitude.
The helicopter was equipped with inflated pontoon-type rubber floats. Initial impact on the right rear float
had sufficient force to bend the cross tube upward. The left, forward rolling action that followed failed the
left float, left chin bubble, and right windshield. The helicopter rolled inverted and the cabin was engulfed
in water immediately. This occurred so rapidly that the pilot and three passengers barely escaped
drowning.
All four survived the mishap, although difficulty was experienced in exiting the inverted helicopter cabin
under water. All four climbed onto the belly of the inverted helicopter, which was floating,
suspended by
the remaining right side float. The pilot had one pocketknife and a butane cigarette lighter in his pocket
and had managed to grab his inflatable life jacket as he exited the helicopter. The three Forest Service
56
employees did not have any survival gear on them. Their personal gear, stowed in the cargo compartment,
could not be retrieved.
They discussed the seriousness of their situation. Standing in water on the bottom of the helicopter,
growing rapidly numb from the cold water, and believing they were being carried out to sea by an outgoing
eight-knot tide, it was evident that none would survive very long. The time was 1330 AST. All agreed
their best alternative was to swim to shore. The current was moving them close, approximately 100 feet, to
Rapids Island. The pilot said, “We better swim for it.”
The pilot and one passenger let themselves into the water and started for shore. Another passenger jumped
in next. The last removed his coat and dropped it over the float, stood up on the float, dove in, and swam as
hard as he could to overcome the current. The others wore their coats. The last passenger to get off the
helicopter reached shore ahead of the others and looked down current. He saw one passenger struggling in
the water past the
island. The float that had broken off was floating near his position so they all hollered at
him to swim for the float. He was last seen, believed holding onto the float, drifting with the current. By
1345 AST, all but this one passenger had made it to the shore of Rapids Island.
There had been no emergency radio transmission from the helicopter to alert anyone about any difficulty.
Consequently, they were suspected of having landed someplace to wait for better weather. Because he
could hear that the dispatcher could not raise the helicopter on the radio, the skipper of the Forest Service
Marine Vessel (M/V) Sitka Ranger boat had asked Dispatch if they wanted him to remain in the area. He
was told they didn’t suspect any trouble and to continue returning to port.
At 1400 AST, when the helicopter did not land at the airport on schedule, Dispatch began overdue aircraft
procedures. At 1515 AST, the skipper of the M/V Sitka Ranger radioed to Sitka Dispatch that the
wreckage of the helicopter had been located upside down in the vicinity of Little Island. This information
prompted an official search to begin.
At 1535 AST, the United States Coast Guard (USCG) dispatched a helicopter with rescue personnel to the
site. Upon diving into the floating helicopter, they found it to be empty and began searching the
surrounding area.
On shore, one passenger was near total exhaustion. He was fully conscious of the trouble he was in and
knew he had to get over the hill to where the other two were sheltering in a root wad. The other two
encouraged him at that point, and he finally made it. He suggested that he try to get a fire going and for the
other two to collect some firewood while they were still able to do so.
It took considerable effort to dry out the lighter before it would work. He placed the lighter under his
armpit for 15 to 20 minutes, trying to warm it up and dry it out. He cut slivers of wood with the knife and
finally got the butane lighter to light and stay lit. It was 1600 AST before he felt they had a fire that they
could keep going, two and a half hours after swimming to shore. They all felt they would survive the night,
if not rescued, since they had a fire.
The survivors took turns watching for signs of a search on the beach. At about 1500 AST, the pilot and one
passenger thought they heard a helicopter, but the sound weakened and disappeared. About 1600 AST,
they heard a helicopter again, getting closer. Then they heard another one and the survivor on the beach
hollered for everyone to get down to the beach to be seen. The USCG helicopter flew by but didn’t see
them. The owner of the mishap helicopter had another helicopter in the area searching and it seemed to be
coming toward them. A survivor waved the yellow life vest but the helicopter never saw them, turned
away, and headed for another bay. The USCG helicopter flew by again at about 1630 AST, heading
directly at the survivor on the beach.
The survivor by the fire had placed some material on the fire that was putting up a lot of smoke. The
USCG had seen the smoke but the passenger on the beach didn’t know that and kept chasing after the
helicopter, waving. He thought they may have been seen but wasn’t taking any chances. The USCG put a
diver in the water to swim to shore and check the survivors. The diver made the survivors stay by the fire
57
and warm up, since they were all experiencing hypothermia. The time was 1700 AST. The search for the
missing passenger continued for at least four days. He was never located.
The investigation team discovered that the pilot had been approved for Forest Service use on April 21,
1986. He had flown a total of 50.7 hours in the previous 90 days. He was an exceptionally well qualified
pilot with over 14,000 hours total flight time. 3,100 plus hours were as the PIC in this make and model of
helicopter.
The helicopter had been flown a total of 52.4 hours since June 16, 1986. The helicopter had been in
extensive major maintenance for approximately eight months. It had just been signed off March 5, 1987,
the day before the mishap. The mishap pilot flew a maintenance test flight of .3 hours on that date. A
flight lasting .6 hours in duration took place the day of the mishap before the Forest Service passengers
boarded the helicopter. The helicopter was not operating on any Rental Agreement or Call-When-Needed
(CWN) contract.
Post mishap inspection of the helicopter revealed that the fuel shut-off valve was in the open position. The
cannon plug from the airframe fuel filter bypass indicator was corroded. The fuel tank was ruptured upon
impacting the water. The fuel boost pump punctured a hole through the top of the bladder. Salt water was
found inside the airframe fuel filter. The filter bowl and the filter were very dirty. The filter allegedly had
been changed during the annual inspection. Salt water was found in the fuel line from the airframe filter to
the high-pressure pump. The high-pressure filter was removed from the engine and disassembled on ‘the
bench.’ A drop of water was found in the filter bowl and was considered too far upstream to have trickled
in while the helicopter was submerged. No water was found in the fuel control unit and governor
connecting lines.
The finger stringer was removed from the fuel control unit and a small piece of dirt was found on the
outside of the screen. This is an inside-to-outside flow filter. Dirt should not have been on the outside.
There was no damage to the governor shaft, the hot section, or the compressor section.
Only one lamp removed from the annunciator panel showed failure while burning. That lamp was the low
rotor rpm bulb. The engine out bulb and cover were missing.
Fuel samples taken at the fuel site where the pilot had refueled the helicopter with 15 gallons of fuel before
the return flight, were found clean and clear. The fuel on board the helicopter should have been sufficient
to reach the airport if they had averaged about 90 mph. The engine de-ice switch was found in the “off”
position. The engine auto-igniter system was inoperative; the switch was off.
The National Weather Service (NWS) in Sitka reported the weather at 0950 AST as scattered clouds at
2,500 feet, estimated ceiling at 6,000 feet overcast (OVC), with another OVC layer at 15,000 feet. Surface
visibility was 15 miles. Breaks in the overcast were visible. Wind was 160 at eight knots. Temperature
was 37 degrees Fahrenheit and dew point was 28 degrees Fahrenheit.
Another pilot in a fixed wing aircraft passing through the area at approximately 1130 AST was forced to
land and taxi on the water because of bad weather: snow showers, low ceilings, and poor visibility.
Weather during the return trip at 1300 AST was reported as intermittent ceilings at 200 to 500 feet with
reduced visibility of one half of a mile in snow. There were occasional heavy snow showers and fog.
Winds were northerly at 20 to 30 knots.
Possible probable causes were determined as: 1) Mechanical failure of the fuel control and governor, 2)
Snow ingestion and blockage of the particle separator, 3) Fuel contamination – as per the small drop of
water found in the fuel drained from the filter bowl and the very dirty airframe fuel filter.
58
The wreckage discovered by the M/V Sitka Ranger boat.
Post-mishap Bell 206BII Jet Ranger being moved into the hangar.
59
On May 31, 1988, a Forest Service job contract pilot and his employee transported their helicopter, a UH-
1B, by trailer to Warm Springs, Oregon. They positioned the helicopter to begin aerial application of
insecticides, Thuricide 32L insecticide (B.T.), for suppression of Western Spruce Budworms. This
helicopter was one of ten aerial application and seven observation/marker aircraft subcontracted to spray
195,000 acres of Oregon, Warm Springs Indian Reservation, and national forest land in the Warm Springs
Unit.
On June 4, 1988, a Forest Service Aviation Safety Inspector called the FAA Flight Standards District
Office (FSDO) in Hillsboro, Oregon. He requested an FAA inspection of this UH-1B spray helicopter due
to concerns he had about its airworthiness. The FAA declined to inspect the helicopter as it was to be
flown on a government project. Forest Service personnel characterized the spray operation as a “Service
Contract” project. Consequently, any aircraft involved were not inspected or carded by a Forest Service
Aviation Safety Inspector as required for aircraft services obtained by an “Aircraft Contract.”
On June 6, 1988, the pilot aborted his first attempted spray mission after experiencing engine surges in
flight. A total time of .2 hours was recorded for that flight. The Project Team Leader’s daily
accomplishment report for this date contained
the comment “engine problems, keep ship from applying.”
The contractor’s employee later reported that a Rotary Wing Application Specialist, the Project Team
Leader, and a Forest Service Manager were aware of the engine problems.
The Spruce Budworm job contract was started up early in the Visual Meteorological Conditions (VMC)
day of June 14, 1988. Forest Service daily flight records showed the pilot, the only occupant of the mishap
helicopter, departed the grass/dirt Old Mill Airstrip on the Warm Springs Indian Reservation at 0515 PDT.
He was loaded with 250 gallons of B.T. for aerial application. As the helicopter left the airstrip, it was
observed to be having difficulties gaining altitude. Nonetheless, the first load was sprayed and the
helicopter returned to the heliport at 0607 PDT.
After refueling and reloading with 250 more gallons of B.T., the pilot took off on his second aerial
application flight of the day. The Forest Service Team Leader, who was supervising the spray operation of
this helicopter from a communications vehicle at the airstrip, later said that he heard the pilot broadcast a
distress call at 0642 PDT over the very high frequency (VHF) radio. Radio traffic on other radios in the
vehicle masked part of the distress call, but he distinctly heard part of the transmission including “…power,
going down, going down.” A search was initiated.
The wreckage was located at 1008 PDT. The mishap took place en route to the aerial application area five
nautical miles (nm) southwest of the loading site. The pilot was fatally injured. The aircraft was totally
destroyed. There was not a post mishap fire.
The NTSB investigated this mishap. Their file number is SEA88FA109.
Upon questioning by the investigation team, the company employee and several other witnesses reported
seeing flames shooting out the helicopter engine exhaust extending at least three to 15 feet during engine
start in the days since the helicopter arrived in Warm Springs. An Airframe and Powerplant Mechanic
(A&P) of another company said the mishap helicopter had starting problems. He said that the engine would
not accelerate to flight idle speed within the maximum starter engage time of 40 seconds, which he
described as a ‘hang start.’
The mechanic said the pilot had energized the starter as long as two minutes in attempts to start the engine.
He reported that after the pilot was unsuccessful on several occasions in starting the engine using the
normal approved procedure, he began placing the governor in the emergency position for starts to get the
engine to accelerate to flight idle speed.
The pilot held an FAA Commercial Pilot Certificate issued on December 8, 1977 with Airplane Single
Engine-Land and Rotorcraft-Helicopter ratings. He held a Second Class Airman’s Medical Certificate that
was issued on May 21, 1988 with no limitations. His logbook contained an entry, dated
Jan. 8, 1988, for
60
completion of his Biennial Flight Review (BFR). According to his logbooks, he had accumulated 9,274
hours total flight time of which 4,701 hours were flown in helicopters, 681 hours in the UH-1B helicopter,
680 hours as the PIC. The pilot did not possess an A&P mechanic’s license.
The mishap helicopter was a United States (US) Army UH-1B helicopter manufactured by the Bell
Helicopter Company under a military contract. This particular helicopter was operated by the military until
it was retired from the active fleet and sold as surplus. A civil certification of the helicopter was affected
by a commercial helicopter pilot training operator with maintenance staff for routine maintenance and
inspection of company aircraft. This maintenance facility did not hold an FAA aircraft manufacturing or
repair station certification. This company applied for and was awarded an FAA Aircraft Type Certificate
(TC) on April 6, 1984 for “Bell UH-1B” helicopters.
The mishap helicopter was assigned a serial number. The origin of this serial number could not be
determined for the certifying FAA office. The helicopter was type certificated in the utility helicopter
restricted category in accordance with 14 Code of Federal Regulation (CFR) 21.25 (a) (2) for the special
purpose of external cargo operations.
The FAA issued a restricted category airworthiness certificate for this aircraft on February 15, 1984. The
certificate listed the serial number and the model as a 204-UH-1B, Bell Helicopter. A review of the
specifications of the Bell 204 and military UH-1B helicopters revealed significant differences in structure,
systems and operating limitations of the two types of helicopters. Purposes listed on the certificate were
agriculture and pest control, aerial surveying, forest wildlife conservation, patrolling, search and rescue,
and external cargo operations.
According to personnel at the FAA Helicopter Directorate, any modification of the helicopter from the
manufacturer’s type certificate, including installation of special purpose equipment, must be documented
by FAA Form 337. The modification must be inspected and approved by an FAA Airworthiness Inspector.
The airworthiness certificate must conform to the restrictions listed on the Manufacturer’s Aircraft TC.
There was not an FAA Form 337 filed for installation of the aerial spray equipment on this helicopter.
There was no record that this helicopter had been inspected and approved by the FAA. There was no
record the FAA office that issued the restricted category airworthiness certificate had inspected the
helicopter for the additional purposes listed on the airworthiness certificate that were not listed on the TC.
The TC listed required equipment for operation of the helicopter. Included on this list were the Military
Operators Manual for the UH-1B and the aircraft check list. Neither document was aboard when the
mishap occurred. The TC required the helicopter be maintained in accordance with military standards.
The engine maintenance manual outlining engine servicing, maintenance, and required checks was not
listed on the TC.
According to entries in the maintenance records, other numbered military technical publications and
inspection checklists designated for use on other UH-1 series military aircraft were used by company
personnel to accomplish required maintenance on the helicopter.
Since new, the helicopter had been flown a total of 7,109 hours. The last recorded annual inspection was
completed on May 4, 1988 at 7,105.4 hours. The maintenance records indicated the helicopter had been
involved in a hard landing as a result of
engine hot section failure on April 25, 1986, at 6,850.3 hours total
time. The landing gear skids and transmission were changed after the helicopter returned to service on July
9, 1986. The engine was removed again on March 9, 1987, at 6,960.8 hours.
The engine in the helicopter when the mishap occurred was installed on March 9, 1987. There was no
record that a baseline Turbine Engine Analysis Check (TEAC) was accomplished as required by the
aforementioned military maintenance manual after the engine was installed to determine maximum N1
(speed of gas producer (compressor) in rpm) limits. There was no record that the pilot was performing a
daily Health Indicator Test Check (HIT) check to monitor engine performance as required by that technical
61
manual. The maximum allowable N1 speeds entered on the Go-No-Go placard posted by the N1 indicator
was dated December 16, 1974. It could not be determined how the pilot computed hand written load charts
found in the helicopter without current TEAC N1 topping information.
According to personnel at the FAA Helicopter Airworthiness Certification Branch, four FAA
Airworthiness Directive’s (AD’s) had been issued for civil certified UH-1B helicopters. There was no
record of compliance with those AD’s in the helicopter logbooks. The president of the TC holder reported
the company has not established a system for distributing AD’s, factory service bulletins, or changes to
military technical manuals to aircraft operators. The TC stated that a report, dated October 10, 1983, listing
Army Modification Work Orders and Technical Bulletins was available from the TC holder and must be
complied with. The president of the TC holder was not familiar with the report and could not provide a
copy when it was requested.
The maintenance records indicated the helicopter was weighed on May 3, 1988. A hand written calculation
of weight and balance after installation of the spray equipment was in the helicopter records. According to
those calculations, the helicopter basic weight was 5,633.2 pounds and the center of gravity (cg) was 129.9
inches aft of the datum. The pilot weight was determined to be 180 pounds. Standard fuel load for this
helicopter was 800 pounds. The helicopter was serviced to 800 pounds of fuel before the helicopter took
off on the mishap flight.
Forest Service records indicated the helicopter was loaded with 250 gallons of insecticide weighing 2,375
pounds. The gross weight at take off was computed to be 8,988.2 pounds. The maximum allowable gross
take off weight listed in the TC and military manuals was 8,500 pounds. The cg range at maximum gross
weight was listed as 125 to 136 inches aft of datum. The helicopter’s cg was computed to be 118 inches aft
of datum at takeoff and when the mishap occurred.
An A&P mechanic from another company later stated that the pilot had requested his assistance in
changing an engine governor after experiencing rpm fluctuations in flight on June 6, 1988. He said the
pilot reported the engine N2 (speed of power turbine in rpm) rpm surged to 7,000 rpm, dropped to 6,000
rpm, and stabilized at 6,500 RPM. According to the Military Operations Handbook, normal operating rpm
at maximum gross weight is 6,600 rpm and maximum N2 rpm is 6,750 RPM. A special inspection of the
helicopter’s power train would have been required when the maximum allowable N2 rpm was exceeded.
There was no record in the helicopter logbook of an over-speed inspection being accomplished. The A&P
stated he had changed the N2 governor. However, the helicopter logbook was not available and he did not
make an entry of the changed governor.
At 0620 PDT, the morning of the mishap, weather at the airstrip consisted of clear skies, temperature 49
degrees Fahrenheit, 81 percent relative humidity, and winds out of the northwest at three to five mph.
Density altitude at the mishap site was computed to be approximately 3,420 feet. Elevation at the mishap
site was 3,300 feet mean seal level (MSL). There was 15 miles of visibility.
The helicopter initially impacted and broke a large evergreen tree 60 feet above the ground on a heading of
055 degrees magnetic. It then traveled approximately 134 feet, breaking several more trees during the
impact sequence, and came to rest on the ground in an upright, nose up attitude with the nose jammed into
a broken tree. The tail boom and main rotor system separated from the main fuselage. The fuselage split
circumferentially through the aft cargo compartment. The roof above the cockpit and aft cabin was
collapsed down to the level of the pilot seat back. The engine compartment separated from the aft fuselage.
The engine air intake filtration system was damaged and the inlet section was open to the atmosphere. The
main power shaft was disconnected at both ends with only minor damage to the spines.
There was no evidence of main or tail rotor impact with trees in the impact area and no significant leading
edge damage to any of the rotor blades. The drive shafts exhibited no torsional damage. The engine power
turbine blades were free to turn clockwise, but locked up when turned counterclockwise. There was visible
damage to the inlet stators and front stages of compressor blades.
62
A fuel sample from the helicopter and service vehicle was visually examined and tested for water. The
sample was clear with no evidence of water or other contamination.
The transmission input quill was rotated to check operation of the free wheeling clutch assembly, which
operated normally. The clutch was removed, disassembled, and examined, revealing normal internal
lubrication: no scoring, discoloration, or damage.
The engine was disassembled and examined at Textron Lycoming, its manufacturer. The power turbine
section contained soot and a buildup of carbon deposits on the fuel nozzles, but no evidence of blade rub,
deformation, or damage indicating over-temperature operation.
Examination of the compressor revealed all but three axial stage compressor blades had separated above the
blade platform. Two small pieces of wood and two small pieces of metal identified as aluminum (#6010)
that is used in fabricating the particle separator were found in the compressor. Examination of the
compressor blades revealed high cycle fatigue in all stages of the compressor.
The governor that was removed from the mishap aircraft, a governor that had been installed before the
mishap, and subsequently removed, and the fuel control unit were tested. According to the report, the tests
revealed deviations from normal specifications in both function and rigging.
The helicopter had been above maximum certified gross takeoff weight and exceeded the forward center of
gravity limit at the time of takeoff.
Wreckage of UH-1B as viewed opposite the direction of impact.
Black and white photocopy.
63
The repeater site in the Cloud Peak Wilderness Area on the Buffalo District in the Bighorn National Forest
in Wyoming was located at 10,205 feet MSL. It was above the timberline among sharp granite boulders of
irregular sizes and shapes.
August 19, 1988 was a clear day with a temperature of approximately 65 degrees Fahrenheit and winds out
of the east at three to seven mph. An Aerospatiale SA315B (Lama) was busy transporting a Helitack
Crewmember, two Communications Technicians, and cargo, which included four repeater batteries
strapped to the floor to the repeater site.
While flying reconnaissance for a proper landing site at 10,000 feet MSL and 100 feet above the terrain, the
helicopter began to spin violently to the left. The pilot was unable to control the rotation and the helicopter
began to descend toward the rocks below. The helicopter descended 400 feet rapidly and rotated four to six
times before the tail rotor guard struck the rocks. The helicopter continued to rotate another 90 degrees
before impacting on an easterly heading at a nearly level and upright orientation with considerable forward
velocity.
The dynamic forces generated by the weight of the passenger in the left front seat on impact caused his seat
belt to fail. This seat belt failed on the outboard side of the left front seat at approximately six inches from
the attachment point. The failed seat belt released the left front seat passenger from the restraint system.
He was subsequently thrown from the helicopter feet first and was propelled into the rotating main rotor
blades.
The main rotor system was still under power after the fuselage impacted the rocks. The rotors contacted
the rocks above the impact site and caused the helicopter to attempt to continue to rotate in a
counterclockwise direction. The fuselage turned upon itself and came to rest heading to the west and
nearly inverted on a 65 percent south sloping aspect of a rocky peak.
One survivor called for help on his handheld radio and directed the rescue helicopter to their location.
Personnel on the helicopter were qualified as follows:
The pilot was properly inspected and approved for SA315B helicopters. He had approximately 150 hours
of PIC time in the previous 60 days. 350 hours of his 2,350 hours total flight time were in the SA-315/316
helicopter. The pilot occupied the right front seat and was wearing the prescribed personal protective
equipment (PPE). He survived the mishap, but sustained injuries.
The Helitack Crewmember on board the helicopter was fully qualified as such. He was on the helicopter to
load and unload the passengers at the destination. His seat failed. He was seated in the left rear seat. He
was wearing PPE. He survived the mishap, but sustained injuries.
The passenger in the right rear seat was the Communication Unit Leader on the fire. He was being flown to
the repeater site to change the batteries in the repeater radio. He appeared uninjured at the time of the
mishap, but was sent to the medical facility for observation. He was wearing PPE. He survived the
mishap, but sustained injuries.
The passenger in the left front seat was a Bureau of Land Management (BLM) Radio Technician Trainee.
The Communications Unit Leader had requested him for fire situation training purposes. He was wearing
PPE. He was fatally injured when he was thrown from the helicopter during the mishap sequence.
The mechanic assigned to this helicopter was an employee of one company on loan to another as a
temporary mechanic replacement. He was fully qualified to maintain the helicopter and was not on board
the helicopter at the time of the mishap.
The SA-315B involved in this mishap was manufactured in June of 1975. The total time on the airframe
was 8,212.1 hours. Total time on the engine was 2,609.3 hours with 4,962 cycles recorded. An FAA
64
Extension Certificate for 250 hours was issued for the engine, extending the time before overhaul (TBO) to
2,750 hours. The next scheduled maintenance was to check the main gearbox chip plug and filter at the
airframe time of 8,216 hours. The next scheduled inspections were a 25-hour inspection at 8,226.0 hours
and a 100-hour inspection at 8,276.7 hours. There were no open maintenance discrepancies being carried
forward or deferred at the time of the mishap.
Examination of the wreckage revealed that the tail rotor drive shaft was broken at the shaft location where
the drive train attached to the fuselage. A fatigue crack in the intermediate coupling shaft was discovered.
Examination of the company’s overhaul and maintenance records showed that an approved FAA Repair
Station installed the shaft in June of 1988 after overhaul. The failed part had 1,224 hours since overhaul at
the time of the failure with a time limit of 1,800 hours between overhaul.
The NTSB analysis of the break revealed a fatigue fracture propagating from a point weakened by chrome
plating, in the radius where the crack began. An Aerospatiale Service Bulletin (Number 01.14) mandated
that shafts with chrome in the radius be removed from service beginning in 1979 and was the subject of the
17
th
Airworthiness Directive for the SA 315 B helicopter. The mishap shaft was checked and approved as
having no chrome in 1985. The Service Bulletin was complied with on May 1, 1985, as bulletin number
01.47, an identical bulletin associated with the SA316 helicopter.
The investigation team found the seat harness of the fatally injured individual with the buckle closed and
belt failure in the webbing. The examination of the seat belts by the NTSB Materials Laboratory revealed
that they were substituted at the factory for the standard inertial reel belts in the mishap helicopter. The
tests of the seat belts found none met the requirement of Technical Standard Order (TSO) C-22, the
standard for aircraft seat belts. Analysis of the seat belt fabric indicated deterioration from exposure to
ultra-violet radiation.
The helicopter was determined to have been loaded within limits specified by the flight manual for the
density altitude of the mishap site.
The probable cause of this mishap was determined to be the loss of power to the anti-torque (tail) rotor.
This forced the helicopter into an uncontrollable spin to the left and impact with large granite boulders.
The loss of power to the tail rotor was caused by the failure of the intermediate coupling shaft assembly,
due to a fatigue crack at the coupling flange. Contributing to the failure was improper compliance with the
manufacturer’s mandatory service bulletin number 01.14.
The probable cause of the fatal injury was the failure of the passenger restraint system, which allowed the
passenger to be thrown from the helicopter upon impact.
65
SA315B tail rotor failure was caused by the failure of the intermediate coupling shaft assembly, due
to a fatigue crack at the coupling flange.
66
At approximately 1500 PDT on July 26, 1991, a Bell 206 LI departed from the Bald Mountain Helitack
Base enroute to a small holdover lightning fire in California. This fire was located north of Alpine Lake in
the Pacific Southwest Region, Stanislaus National Forest. On board the helicopter were the pilot, helitack
crewmembers, and initial attack response equipment. After landing the crew in a meadow near the fire, the
pilot had the water bucket hooked on and commenced dropping water from a nearby lake onto the fire.
Approximately one and a half hours after arriving at the fire, the pilot had made 12 bucket drops. The pilot
was then told to longline two pillow tanks of water to the fire. The pilot left the water bucket at the
meadow helispot, picked up a helitack crewmember, and returned to the helibase for the needed equipment
and to refuel. On the way, the pilot was asked what length longline he would need and he indicated the
100-foot line would be enough.
After refueling and loading two 100-gallon pillow tanks, a 100-foot longline, and the remote hook, nets and
associated equipment, the pilot and the crewmember returned to the valley. The equipment was unloaded
and readied for filling and pickup. The pilot flew back to the meadow helispot near the fire, picked up two
more helitack crewmembers, and returned them to the helibase. On this trip, the pilot circled the fire and
the person on the ground indicated where he wanted the tanks placed: a small opening enlarged by falling a
large lodge pole pine. The opening was quite close to the fire line on the north side and the intent was to
hook a hose to the pillow tanks and gravity-feed water to the fire. The pilot radioed the valley that the 100-
foot longline would be okay.
The tanks were filled from an engine at the valley and helitack crewmembers prepared the longline load.
While most of the engine crew had been shuttled to the fire by another helicopter, a Foreman had remained
with the engine. The Foreman operated the engine and monitored the tank gauge to insure that only 75 or
80 gallons were put into each tank, as directed. Helitack crewmembers verified that the pillow tank was
about six or seven inches high when filled, which, according to their training, would correspond to 75
gallons.
At liftoff, the helicopter gross weight was within established limits for the density altitude at the load
landing spot. The load calculation for this flight was completed after the helicopter took off and was not
reviewed or signed by the pilot.
The pilot took off and lifted out the first pillow tank about 1700 PDT. The pickup and departure appeared
normal. He circled over the meadow helispot. His approach was apparently slow and his descent fairly
steep as he brought the load in over the lower trees on the northeast side of the opening. During the flight
the pilot had commented by radio, “It’s really squirrelly up here today.” And, on short final, “Don’t get
under this load.” The person on the ground, preparing to direct the setting down of the pillow tank, did not
hear the first comment, but answered, “okay” to the second.
As the helicopter came to a hover, the load hit the ground somewhat harder than normal and a few feet
north of the spot previously indicated to the pilot. The pilot disconnected the remote hook electrically and
the helicopter rose slightly and moved forward a few feet. The helicopter skids were about 16 feet higher
than the top of a 90-foot tree on the pilot’s right at the point where the load touched the ground. The plane
of the main rotor overlapped the treetop by approximately two feet. There was a 106-foot snag-top tree
about 40 feet in front of the helicopter.
While still in a hover, the helicopter began to wobble and tilt, first to the right and then to the left, and then
began to descend vertically. The witnesses observed that the engine and/or rotor noise changed noticeably.
The pilot keyed his mike and in a distressed voice called out, “Get out of the way!”
The helicopter continued to descend and the main rotor hit the 90-foot tree about four feet from the top.
Further strikes occurred progressively down the tree. As the helicopter descended to about 50 feet up the
tree and turned to the right, the main rotor began disintegrating and cut off the tail boom.
67
At approximately 40 feet, the helicopter pitched nose-down and free fell to the ground on top of the pillow
tank and longline. The impact was relatively hard. The helicopter ended upright and at least 45 degrees
nose down. The main rotor blades were at a high pitch or angle of attack during all of the tree strikes.
Two crewmembers from the engine were on scene immediately. They noticed the helicopter engine was
still running at flight idle and a moderate amount of fuel was leaking out. The cabin floor was pushed
upward by the force of impact. The pilot had been fatally injured.
The pilot was qualified and properly approved for the Bell 206LI and for longline missions using a remote
hook. On the date of his Office of Aircraft Services (OAS) interagency inspection, he had 12,200 hours of
helicopter PIC time. All these hours were in weight class less than 6,000 pounds. It was determined that
he was not fatigued or unusually stressed at the time of the mishap mission. He did not become
incapacitated during the flight.
The helicopter was properly inspected and approved. There were no known mechanical defects that would
affect flying performance on the day of the mishap. All damage and defects found in the wreckage
examination and component analysis resulted from the helicopter’s impact with the tree strike and the
ground. Fuel on board the helicopter and in the contractor’s fuel truck was not contaminated.
The fire area and mishap site were in the head of a large, wide, relatively flat drainage with higher ground
on three sides. The spot chosen and improved for landing the longline loads was adequate in size, but some
of the surrounding trees were significantly taller than estimated by personnel on the ground (90 to 100 feet
tall). The mishap site was in an area characterized by fairly dense stands of large, tall lodge pole pine, and
other smaller trees interspersed with small and large meadows and natural openings, at an elevation of
about 7,600 feet MSL.
The day was clear and sunny and there was little smoke obscuration near the fire. At the load touchdown
point, the helicopter was in direct sunlight but the ground was in deep shadow. Winds at ground level were
southerly at zero to six mph. Winds were somewhat stronger at treetop level. There was indirect evidence
of 180-degree wind shifts several times per hour, turbulence, and possibly wind shear at tree lines. A
thunderstorm had passed through the area earlier and buildups were visible about 20 miles away.
Temperature was reported at 20 degrees Centigrade.
In developing a probable cause to this mishap, the investigation team stated that the flight profile of the
final approach to land the load in the opening was conducive to the helicopter entering into a main rotor
vortex ring state that was aggravated by a shift in direction or down draft in the wind. This could have
caused a descent beyond the pilot’s capability to arrest in the vertical space available to perform an escape
maneuver. They deemed the mishap was caused by the strike of the main rotor blade near the top of a tree.
View of Bell 206LI from center of opening. Tree felled prior to mishap to enlarge opening.
68
July 12, 1994 was a hot day on the Gila National Forest in the Southwestern Region. The temperature was
determined to be 90 degrees Fahrenheit at the helispot at 9,520 feet.
At about 1500 MDT, an initial attack helicopter, a Bell 206LIII, arrived over a newly reported lightning
fire. The fire was located in rough mountainous terrain at an altitude above 8,500 feet and a few miles
from a large project fire. The pilot and four-person helitack crew sized up the fire from above and radioed
this information to the Silver City, New Mexico Dispatch Center. The pilot then made a high and low level
reconnaissance over the 9,520-foot helispot, which was less than a quarter of a mile from the fire. The
helispot was located at the south end of a steep northwest-southeast oriented ridgeline. An approach to the
helispot was initiated in a west-northwest direction and the pilot attempted a landing.
Upon completing the approach, the helicopter came to a 10 to 20 foot hover over the helispot. This hover
was followed immediately by a pronounced flaring of the helicopter to a nose high attitude. The helicopter
then started to turn to the right and slide backward. The right turn rapidly became a spinning motion. It
was reported that occupants of the helicopter heard a loud crack like noise after one or two full turns. The
helicopter was soon one hundred yards immediately east of the helispot, adjacent to the original approach
path, over a measured 70 percent slope that was thickly populated with pine and fir trees, oak brush, rocks,
and other vegetation.
The helicopter continued to spin, descending almost vertically with the fuselage reasonably level until the
rotor system severed two medium sized trees 10 to 12 feet above the ground. The nose of the helicopter
impacted the ground sharply with the tail rotor pointing away from the slope. After initial impact, the
helicopter slid approximately 70 feet, coming to rest against a large tree. The wreckage was positioned on
a measured heading of 040 degrees from the intended landing spot at a distance of 350 feet.
There were five occupants on board the helicopter. At the point of impact, one passenger was thrown from
his right rear seat, tearing loose from his seat belt. He fell into a prominent “gully” in the ground
immediately below the helicopter impact point. He survived and remembers seeing the helicopter pass
over him as he lay in the gully. He then ran from the scene, climbing frantically uphill around the south
side of a prominent large rock dominating the immediate landscape.
The four remaining occupants remained inside the helicopter as it slid down the steep hillside. Of these
four, one survived. This passenger remembers unbuckling his seat belt, exiting the helicopter to the south,
and climbing up the hill, south of the big rock. There was no immediate fire.
Personnel involved in the mishap included:
The pilot, who was carded in April of 1994, had a total of 4,270 hours flying helicopters, all in the Bell
206LIII. 3,100 of these hours were in mountainous terrain. He had flown 29.1 hours between July 7
th
and
July 12
th
. He had been working an average of 14 hours each day for those five days. He was seated in the
right front seat and was fatally injured.
The helitack crewmember, the left front seat passenger, had nine years of fire experience. He was fatally
injured. The left rear facing seat passenger, an Administratively Determined (AD) Firefighter, was fatally
injured. The AD Firefighter seated in the left side last aft seat in the rear compartment had four years of
firefighting experience and survived the mishap. The other survivor was seated in the rear compartment,
right seat aft. He was also an AD Firefighter. There was loose cargo between the seats of the very aft row
of firefighters.
After both survivors climbed to the top of the ridgeline, one used his shirt tied to a stick as a signal to
rescuers. Both reported popping sounds after leaving the helicopter, but did not observe wreckage smoke
until later. There was a post-mishap fire. Both survivors were rescued.
Both surviving crewmembers reported that the approach was made in relatively stable conditions until they
were immediately over the intended landing spot. One surviving crewmember reported that he felt the
69
approach was made downwind. During prior flights, another pilot had observed this pilot making
downwind approaches. Other pilots had previously counseled the mishap pilot against accepting heavier
loads than he should have and for flying after dark.
A five-gallon cubitainer of water, a Dolmar container with one and a half gallons of gasoline, and two and a
half quarts of oil were carried unsecured on the floor of the main passenger compartment.
One load calculation had been prepared for July 12
th
for an altitude of 8,500 feet and 28 degrees
Centigrade. Reconstructed load calculations for the actual elevation, temperature, and operating conditions
exceeded the performance limitations of the helicopter. The calculated weight of the helicopter at the time
of the mishap was 3,750 pounds, which included the ‘as equipped’ weight of 2,440 pounds, plus the weight
of the pilot, a fuel load of 265 pounds, and a manifested payload of 875 pounds.
The allowable payloads for the flight were computed using the interagency helicopter load calculation
method. Using a pressure altitude of 9,520 feet and 32 degrees Centigrade, the maximum gross weight to
hover in ground effect (HIGE) was 3,580 pounds (allowable payload of 525 pounds), and a maximum gross
weight to hover out of ground effect (HOGE) at 3,515 pounds (allowable payload of 460 pounds).
However, normal initial attack loading of this helicopter was indeed, four firefighters. Although the pilot’s
name was found on the carbon copy of the helicopter load calculation, it was not on the original copy.
Interviewed helitack crewmembers stated that if conditions at the intended landing site were determined to
be unsuitable, it was normal procedure to land at the nearest suitable site and shuttle personnel. It is
believed that this helicopter may have been overloaded for actual conditions encountered at the initial
attack landing site.
Shoulder harness restraints were built into this Bell 206LIII, but were not used by rear seat occupants.
Shoulder harness restraint in the rear passenger compartment was not a requirement of this contract.
The pilot wore a flight helmet; all other occupants wore hardhats with chinstraps. All occupants wore all
other required PPE.
Post mishap engine teardown analysis indicated that the engine and tail rotor drive were functioning at the
time of the mishap. The helicopter was operating with all the doors removed. The helicopter had been
properly carded and properly maintained.
The NTSB and parties to their investigation team determined mission oriented personnel influenced the
pilot to perform tasks that were unsafe. The actual probable cause(s) were not listed on the report. The
NTSB report number: FTW94FA232.
70
Wreckage distribution of Bell 206LIII.
Arrow: (a) Slope below impact point (b) tail boom
(c) final resting point.
Engine transmission, blade grips, and mast of Bell 206LIII.
71
On September 23, 1994, a Boeing Vertol CH-47D (Chinook) helicopter belonging to the United States
Army in the state of Washington was working diligently on firefighting activities on the Payette National
Forest in the Intermountain Region near McCall, Idaho. It was daylight, the visibility was three miles and
winds were variable at five to eight knots. It was a day.
At 1745 MDT, the Chinook was setting up for a mission to transport Forest Service fire crews. Fire
suppression bucket work was to follow the transport mission. The helicopter departed the helibase with a
bucket externally attached. The helicopter crew’s intention was to leave the bucket at the helispot,
transport three Forest Service fire crews, then retrieve the bucket and proceed fire suppression activities.
Upon arrival at the Davis Ranch helispot, the US Army pilot sat the external load (bucket) on the ground
and moved the helicopter to the right of it to land. After touching down and still “light” on the wheels, the
tail of the helicopter rose slightly in the air with the front landing gear still on the ground. Immediately
following, the tail rapidly went over
the top of the helicopter. The helicopter came to rest upside down and
laying on the top right side. The back of the helicopter was located where the nose was during the
attempted landing. During the mishap sequence, a front rotor blade impacted the left side of the fuselage,
entered the passenger compartment, struck, and fatally injured a US Army Reserve flight engineer.
Of the many firefighters on the ground waiting for transport, none reported injuries. They had been located
150 to 200 feet away from the helicopter landing zone and quickly evacuated the area during the mishap
sequence.
Of the five occupants on board the Chinook, one flight engineer was fatally injured and another received
serious injuries. Two pilots and a National Park Service (NPS) Helicopter Manager received minor
injuries. The helicopter was totally destroyed.
The Captain had a total time in all aircraft of 8,100 hours. 7,110 of these were as the PIC hours. He had
1,537 hours in rotorcraft. The Copilot had a total time in all aircraft of 6,500 hours, 3,000 of which were as
the PIC.
The Military Aviation Safety Center conducted this mishap investigation.
72
Chinook helicopter during mishap sequence.
Photo taken by a firefighter awaiting transport.
73
The day was October 29, 1996 and the Bell 47 Soloy grass seeding job contract for the Forest Service was
well underway on the Fish Lake National Forest, south of Fillmore, Utah. This helicopter and pilot had
already completed 20 missions of spreading grass seed and had refueled two to three times. At the time of
the mishap, the bucket had just been reloaded for its 21
st
flight of the day.
As per job contract expectations, this job contractor supplied the personnel to accomplish the reloading of
the seeding bucket. On this 21
st
reload, the contractor’s two ground personnel performed reloading of seed
into the seed bucket as they had done all day. After loading the seed, one ground crewmember moved to
the front of the helicopter and behind a large rock. The other ground crewmember moved to the right of the
helicopter, near the stack of seed bags. He then turned his back to the helicopter with his head down to
avoid rotor wash from the helicopter as it lifted off.
Three Forest Service personnel were located 50 yards downhill from the helicopter loading area. As per
the stipulations of the job contract, they were not involved in the operation except for the delivery of seed
bags to the contractor’s ground crew. The Contracting Officers Representative (COR) was on site to
provide contract administration. The Forest Service Manual (FSM) 5700 specifically required Forest
Service personnel to limit involvement in aviation job contracts.
The 21
st
reload took place at around 1547 hours Mountain Standard Time (MST). The pilot, flying from
the left seat, lifted the helicopter to a hover. One Forest Service employee observed the attachment cable
over the right skid while the helicopter was coming to a hover. The Forest Service witnesses observed the
helicopter lift off and noted that the bucket suddenly spilled to the side, seed was being dropped from the
tilted bucket from the top left side. The Forest Service personnel observed that the pilot was having
problems controlling the helicopter and it seemed to be swinging out of control. The pilot, attempting to
control the unbalanced lateral cg, continued to add power. The helicopter gained altitude and moved
forward until it impacted the hillside in front and to the right of the landing/departure area. The helicopter
then rolled down into scrub oak trees.
The helicopter impacted nose down and slightly on its right side. The mishap site was on a near 45 percent
slope with several rock outcroppings and heavy loose rock. The initial contact appeared to be with the
main rotor system and cockpit simultaneously. It was then observed to roll over while sliding down the hill
and came to rest in an upright position against a small tree. There was not a post crash fire. The pilot
survived the mishap, but was seriously injured. The helicopter was destroyed.
The district was notified of the mishap and an ambulance and law enforcement were requested. The pilot
remained buckled into his seat and crewmembers extricated him from the wreckage. He was given first
aid. Emergency Medical Technician’s (EMT’s) arrived, rendered advanced emergency treatment, and
transported him to the hospital. He later succumbed to his injuries.
The pilot was the owner of the company. At the time he was issued an OAS card, he had accumulated
helicopter flight hours of 8,000 plus as the PIC. He had a total PIC time of 5,000 plus hours in the Soloy
47.
The pilot was not wearing a Nomex flight suit, but was wearing a snowmobile suit and gloves. He was not
wearing a helmet on this job contract, nor was he required to. The Forest Service personnel observing at
the contract site had asked the pilot to wear his helmet. The pilot had said that it gave him a headache and
it was uncomfortable to look down at the bucket with it on. According to the Office of the Medical
Examiner, his cause of death was craniocerebral injuries.
The mishap investigation determined that a formal system of lifting procedures, including critical pre-
departure checks by ground personnel, were not apparent during the performance of this job contract. A
formal written safety plan was not written and was not required. The owner/operator had sole authority to
determine the operating site. Other than the divided reloading duties of the ground crew, there were no
formal arrangements regarding organization or management of the operating base.
74
The only communications the pilot had with his ground crew were visual signals. There were no helicopter
operations communications with Dispatch during the entire reseeding project. The Forest Service COR
monitoring the seeding project provided radio contact between the operating location and Dispatch.
There was no evidence found to indicate structural failure prior to impact with terrain.
It was determined that the pilot was unable to control the helicopter and flew into ascending terrain. The
helicopter had exceeded its lateral cg limitations due to the external load; the cable hooked over the landing
skid. The contractor’s procedures for loading and clearing the helicopter for departure were inadequate.
Agency policy did not provide for aviation management or oversight of job contracts.
Bell 47 Soloy wreckage resting in oak brush.
Black and white photo.
75
In the evening hours of July 5, 1997, the Sierra National Forest Helitack/Rappel Crew were ordered to an
incident on the San Bernardino National Forest in the Pacific Southwest Region. In the morning, July 6,
1997, the crew left their base.
The Assistant Helicopter Manager and two of the crewmembers accompanied the pilot in the Bell 206LI.
The remaining three crewmembers drove in their crew truck. The company fuel truck departed for the San
Bernardino as well.
The fire was burning in front country hills ranging in elevations from 1,600 to 3,600 feet MSL. This fire
was reported to be the third fire in the past 20 years on this particular site. Terrain was relatively steep,
rocky, and covered with flashy fuels. Drainages were deep and winding, heavier fuels were found there.
Access was poor. There were a few roads except to the very lowest of slopes.
The helicopter arrived at the Patton Helibase at 0900 PDT local after approximately two hours of flight
time. The pilot then flew a total of six reconnaissance (recon) and cargo flights between 1000 PDT and
1600 PDT, totaling two hours 41 minutes of flight time. He refueled with 47 gallons from another fuel
truck already at the helibase in the morning and 39 gallons from his own fuel truck at 1430 PDT.
Just before 1630 PDT, while the pilot was loading passengers for another recon flight, his mission was
changed to water dropping. The pilot refueled again, putting 14 gallons in from his own truck. He then
departed with a Bambi bucket and about 250 pounds of fuel.
Operating conditions for water dropping in the vicinity were not especially difficult or hazardous.
However, the terrain was steep, broken, and almost entirely lacking suitable emergency landing spots.
The weather at this time was reported as VMC. It was daylight, the visibility was ten statute miles or more,
the temperature was 94 degrees Fahrenheit, and wind was from the south at eight knots. No gusts were
reported; however, winds were increasing somewhat with the normal afternoon thermal effect. There was
haze and smoke, but it wasn’t smoky enough to seriously limit aviation operations. Smog and haze at the
lower elevations restricted visibility to a minor extent. Density altitudes in the fire area were not
significantly limiting helicopter payloads.
Another helicopter pilot and the Bell 206LI pilot filled from a water source about four miles west of the
canyon. The other pilot dropped first, working the south side of the spot and dropping on the contour along
the east side of the canyon, down canyon into the southerly wind.
The Bell 206LI helicopter was carrying a 140-gallon bambi water bucket attached directly to the belly hook
by its 12-foot suspension lines and control head. The bucket cinch strap was not tightened to an
intermediate position, so the bucket was capable of being filled to its full capacity. When he was finished
filling, he was carrying about 1,100 pounds on his hook. He was capable of carrying about 1,250 pounds
allowing for fuel burn
off.
As the other pilot flew west after his drop to dip another load, he saw the Bell 206LI loaded and inbound to
drop in the same area. Before the other pilot passed over the ridge west of Sand Canyon (about 1705 PDT),
he heard someone say, “…flame-out….” over the radio frequency. It sounded to him like the Bell 206LI
pilot. He radioed “…..are you all right?….” He heard “ …..flameout – going down….” The other pilot
immediately turned back across the canyon to try to locate the Bell 206LI. While circling the spot fire drop
area, he saw a column of dust further down the canyon and began flying that way. An Air Attack
Supervisor also saw the dust. Each called in a “Mayday.”
After initial impact, the mishap helicopter moved downhill a few feet to the top of a steep bank or cliff, fell
to the bottom of the cliff, and slid or rolled about 20 feet further down the slope before coming to rest. The
pattern of damage appeared to indicate the right side of the helicopter, and perhaps the top as well, struck
the ground during its movement after initial impact. There was no fire. The tail rotor assembly broke away
from the tail boom early in the sequence and was found under the nose. The tail boom broke off close to
76
the fuselage and ended up lying fairly intact down the slope below the main wreckage. The bambi bucket
control head was still attached to the belly hook on the helicopter after the mishap sequence ended.
The Bell 206LI pilot was found still strapped in and slumped out of the right side of his helicopter. His
living space had been severely compromised by significant structural collapse and crushing. His seat pan
had crushed. He was fatally injured.
The investigation process determined that at the beginning of the mishap sequence, the pilot was either
about to drop his load of water or had just done so on the spot fire on the east side of the canyon. He would
have been perhaps 100 feet above the ground, part way up the canyon side. The investigation team
determined that he experienced a loss of engine power and began an autorotation down the canyon, looking
for an opening in the bottom to land in. During this autorotation, the pilot radioed twice that he had a
flameout.
The pilot was able to maintain autorotative flight for one third of a nautical mile down the canyon before he
struck a steep, rocky slope approximately 120 feet above the bottom of the canyon. The initial impact
appeared to have been extremely hard, with the helicopter parallel to the slope or tail-down. The pattern of
the main rotor and tail rotor damage suggested that the main rotor was rotating quite slowly and not
producing enough lift to keep the helicopter flying at the time of initial impact.
The pilot had taken the previous two days off duty. On the day of the mishap, he had flown 6.8 hours. He
had close to 10,000 hours flying as the PIC, more than 4,000 hours of experience in mountainous terrain,
and 2,900 hours as the PIC in Bell 206 series helicopters. The pilot had been wearing all required PPE and
had exhibited a safety-sensitive and professional attitude.
The helicopter was inspected and approved under the contract on April 8, 1997. It had been flown
34.9
hours on the contract since inspection and approval. Power checks indicated satisfactory engine
performance. There had been no mechanical incidents or shortcomings since the beginning of the contract
period. On the first flight of the day on July 4
th
, the engine would not start on the first attempt. This also
occurred on July 6
th
, the day of the mishap.
The company fuel truck had been inspected and approved on April 8
th
. Fuel samples taken after the mishap
from tank and filter exhibited no visual contamination indication.
The Forest Service investigation team researched the possibility of “oxygen depletion,” causing an engine
failure. An engine manufacturer (Allison 250 engine) combustion engineer was contacted. It was reported
the oxygen in the atmosphere would have to have been 95 percent depleted to cause the engine to fail.
About the only place that this condition, 95 percent depletion, could exist is very near to flame. Given the
reported conditions over this fire at the time of the engine failure, it is very unlikely that oxygen depletion
occurred.
The NTSB conducted the factual investigation, case number LAX97GA235. They reported that the fuel on
board might have been critically low at the time of mishap. However, fuel gauges at takeoff indicated fuel
enough for more than one hour of flight. They found that an interruption of the fuel flow occurred, causing
the beginning of the mishap sequence.
The Forest Service investigation team also determined that the direct or proximate cause of the mishap was
the helicopter engine’s loss of power.
At the time the Forest Service report was written, the investigation team had been unable to determine why
the engine lost power. Given the fact that the engine test revealed no discrepancy that would have caused
the power loss, they also concluded that an interruption of the fuel flow occurred. The team concluded that
at the time of the mishap the helicopter was low on fuel. The cause was unknown.
77
Close-up of Bell 206LI mishap site. Tail rotor actually found under nose and moved to permit access
to cockpit.
78
On June 24, 1998, the Tennessee State Governor’s Drug Task Force was conducting drug interdiction
operations in a mountainous area of the Cherokee National Forest in the Southern Region. A Tennessee
Army National Guard (TANG) OH-58A (Kiowa) helicopter and pilot were being used to support ground
crews in these operations. Since the operations were taking place on National Forest System lands, a Forest
Service Law Enforcement Officer (LEO) was participating as a member of the task force. He was on board
the helicopter.
The Drug Task Force was made up of several cooperating agencies for the purpose of locating and
eradicating marijuana being illegally cultivated in the state of Tennessee. The TANG provided support to
the task force in the form of aircraft and personnel. When the task force operated on Forest Service System
Lands, the Forest Service participated as a full member of the task force, providing personnel and other
resources to aid in marijuana eradication efforts.
During the afternoon of June 24
th
, the Task Force’s operations primarily consisted of using the helicopter
with an on board observer to locate illegal marijuana cultivation sites. They were then to direct ground
crews to the cultivation sites so they could be eradicated. At approximately 1430 hours Eastern Daylight
Time (EDT), the LEO had boarded the helicopter as the observer for the operation. At approximately 1637
EDT the helicopter departed the Tri-Cities Airport after refueling the helicopter. Before departing, the pilot
received a weather advisory for fast moving severe thunderstorm activity in the area for the next several
hours. At approximately 1732 EDT, the NWS issued a thunderstorm warning for two counties,
Washington and Sullivan.
The helicopter returned to the site of a located marijuana garden to guide the ground crew in. Operations
proceeded normally. At approximately 1745 EDT, the pilot told the ground crew he had to leave the area
due to deteriorating weather conditions. Ground personnel reported that a storm had moved into the area
and it was raining by the time the helicopter actually departed the area. The helicopter left the sight of the
ground crew heading in a northeasterly direction and did not turn while still within sight. Thirty to forty-
five seconds later, the ground crew heard another radio transmission, “Oh shit,” from the helicopter.
Ground personnel reported that the weather had become severe immediately after the helicopter departed
and lasted for 15 minutes. It was reported that trees up to three inches in diameter were bent horizontal by
the wind event.
No further communication was heard from the helicopter and attempts to re-establish radio contact with it
were unsuccessful. At approximately 1830 EDT, the Tennessee Highway Patrol initiated a search and
rescue operation to locate the missing helicopter. When initial attempts failed to locate the helicopter,
personnel and units from many cooperating law enforcement agencies and other sources joined the search
and rescue operation. The search and rescue operation continued until June 27
th
, when at approximately
1630 EDT, the helicopter wreckage was located in a creek drainage.
Both occupants were killed as a result of the mishap. Their cause of death was massive trauma, which had
occurred during the mishap sequence.
Aviation operations were under the direct control of the TANG. The mishap helicopter was owned and
operated by the TANG. The comparable civilian model of this helicopter is the Bell Model 206, Jet
Ranger. The Kiowa helicopter was painted non-reflective dark green with no high visibility markings.
This made it very difficult to find during search and rescue operations, even when very close to the
wreckage. The dense dark green canopy and the helicopter’s paint scheme masked the wreckage and
contributed to the length of the search. The helicopter was properly maintained by military standards.
The pilot was a Tennessee Army National Guard Captain. At the time of the mishap, he occupied the right
front seat of the helicopter. He was rated to operate this helicopter and had accumulated approximately
4,135 total flight hours of experience. Of that time, approximately 1,295 hours were in rotor wing aircraft
and 600 hours were in the OH-58A. He possessed an Air Transport Pilot (ATP) fixed wing aircraft pilot
certificate. His flight medical certificate was current with an expiration date of November 1998.
79
The pilot and helicopter in this mishap did not have a current approval for use in Forest Service aviation
operations as required by FSM 5712 and FSM 5713. However, the pilot and helicopter did meet Forest
Service requirements for approval of military pilots and aircraft.
The Forest Service LEO was trained and certified. He was assigned to work with the Governor’s Drug
Task Force. He occupied the left front seat of the helicopter. His LEO qualifications were current and he
had authority to enforce laws related to the production, possession, and/or trafficking of controlled
substances on National Forest System Lands. He was also a trained and qualified Forest Service Project
Helicopter Manager. He was not wearing any Nomex PPE. He was wearing a flight helmet.
The mishap area was steep mountainous terrain at approximately 2,600 feet MSL. Foliage coverage was a
continuous canopy of deciduous trees with dense undergrowth and reproduction. The wreckage was
located in a drainage about .8 miles east of the site where the helicopter was last seen by ground crews.
The helicopter had contacted trees on the northeast side of the drainage, losing the main rotor. The rest
of
the helicopter continued airborne to impact the southwest side of the drainage at approximately 3,100 feet
MSL. The top of the ridge was 3,850 feet in that area. The wreckage rolled approximately 70 feet down
the steep sloping terrain where it came to rest against a tree about five inches in diameter in an inverted
position.
The LEO was ejected from the wreckage at the point of impact and was found about 15 feet up slope of the
helicopter. The pilot remained in the wreckage. The ELT had been destroyed on impact and did not
function to aid in the search.
Essentially, the helicopter remained intact with the tail boom attached, but twisted upright. The nose of the
helicopter was destroyed back to the pilot cyclic control on the right side and back to the left seat on the left
side. The main rotor was found on the opposite side of the drainage 100 feet northeast and below the main
wreckage site. The blades were attached to the rotor head and the mast was severed just below the trunion.
The helicopter sustained massive impact damage as the result of sudden terrain and vegetation impact. The
main rotor head and blades were found separated from the main fuselage wreckage that suggested an in-
flight separation. The main rotor mast was found fractured approximately one eighth of an inch below the
main rotor splines. The fracture surface that remained with the main rotor head exhibited areas of typical
overstress and a smooth flat surface that appeared highly polished.
Metallurgical analysis indicated that the end of the shaft had a fracture surface with two areas of differing
appearance. The smooth flat area showed no fracture information when viewed with a binocular
microscope. The flatness and 90-degree fracture angle to the surface raised concerns of fatigue as being
possible in this area. The other half of the rotor head end fracture had obvious smearing marks, with a
center of rotation about a point. Also noted was twisting of the shaft between the two spline sections.
The transmission end of the fracture essentially matched the upper fracture surface, except for one large
bump and the scratches sustained as the result of terrain impact. The tail rotor drive system showed signs
of extensive impact damage with no significant indication of rotational damage. Engine external and
internal examination found no indication of pre-existing defects. The compressor stator vanes were found
contaminated with metal debris and covered with dirt deposits, which suggested that the engine attempted
to run while ingesting dirt and metal contamination.
The splined turbine shaft sheared as the result of torsional and compression overstress. The gas producer
and power turbine rotors showed signs of molten metal deposits consistent with foreign object
contamination. The extensive Kaflex drive shaft damage, internal engine damage, pylon isolation mount
scarring, and internal transmission gear scarring suggested excessive transmission displacement.
The massive fuselage damage was considered terrain impact related damage. The suspected main rotor
mast separation occurred as the result of sudden vegetation contact not as an in-flight separation. The
possible fatigue found in the main rotor mast fracture surface might have weakened the mast structure.
80
The United States Army Safety Center conducted the factual investigation.
OH-58A Kiowa fuselage wreckage.
81
July 30
th
, 2002 found this Aerospatiale AS315B (Lama) flying bucket support on a fire southeast of Estes
Park, Colorado in the Arapaho/Roosevelt National Forest under a CWN contract with the Forest Service.
The helicopter had been refueled and departed from the staging area near Estes Park to apply water along
the fire’s boundary at approximately 1840 hours Mountain Daylight Time (MDT). VMC prevailed.
At approximately 1845 MDT, witnesses heard a “high pitched whining and a rrr-rrr sound, followed by
“whoop, whoop, whoop” sounds. They saw a “bluish/purplish” colored flame coming from the exhaust
stack of the helicopter’s engine.
Witnesses heard the pilot give a warning over the radio, “Helicopter going down.” They heard a high-
pitched whine and saw the main rotor blades turning slowly as the helicopter descended.
The helicopter lost engine power and impacted wooded, relatively level terrain at an elevation of 8,500 feet.
A post impact fire ensued and was quickly extinguished. The fire caused additional damage to the
helicopter.
The pilot, the sole occupant of the helicopter, was fatally injured upon impact. He had been wearing
personal protective equipment and was restrained by a four-point harness seatbelt.
The NTSB, FAA, and Forest Service were continuing their investigation into this mishap at the time this
booklet was printed. The NTSB file number is DEN02GA085.
Aerospatiale AS315B wreckage.
82
LEARNING
EXPERIENCES
Section Three
OTHER
FATAL
MISHAPS
83
October 17, 1974 was a fairly typical weather day in the Ketchikan Area of the Tongass National Forest in
Alaska. There was reportedly a 2,000 to 3,000 solid overcast layer of clouds around Thorne Bay (TRB),
Prince of Wales Island. It was flat calm except for occasional winds to two knots from the southeast.
There were scattered fog patches and the temperature was 45 to 50 degrees Fahrenheit.
A Forest Service contracted DeHavilland DHC-II (Beaver) on floats was descending into TRB as a
helicopter was taking off. Another pilot of the same company, also in a Beaver, landed shortly after the
Forest Service Beaver, on a separate mission. The second pilot had made a short, low altitude flight,
landed short, and taxied through the fog bank at the mouth of TRB. The pilots had a brief discussion.
There was turbulence near the mountains approaching Thorne Bay. There was a dense fog cover near
TRB; however, part of the bay was open.
The Forest Service Beaver departed TRB at 0850 hours Alaska Daylight Time (ADT) in a southerly
direction with a pilot and six Forest Service personnel on board beginning a Visual Flight Rules (VFR)
personnel transport mission. The Beaver, on step, made a turn to the left in the vicinity of a rock island and
lifted off in an easterly direction. Shortly after taking off, the aircraft entered into a fog bank and within
one minute had struck a tree, which detached 18 inches off the right wing tip. After striking four more
trees, the aircraft plummeted nose down to the ground, flipped, and twisted over onto its right side. The
aircraft came to rest pointing back toward its point of liftoff.
At the point of impact, the treetops were at 300 feet in elevation, the highest point in the flight path. The
ground was steep and littered with downed timber. The mishap site was about 200 yards from the beach.
Sometime after hitting the first tree, probably at the time of ground impact, two rear seated occupants were
thrown free of the aircraft. The impact caused severe traumatic injuries to the persons on board, which
resulted in the deaths of the front seat occupants. The three occupants in the second row also received
severe traumatic injuries, which resulted in their deaths.
The two occupants who had been thrown free of the aircraft during t