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Factor affecting the capacity to jettison an S92 push-out window
Abstract
The need for human factors research within global offshore helicopter operations cannot be understated.
Presently, there is extremely limited information about the force required to jettison a helicopter exit.
This information should be readily available in the helicopter design information. This study explored
factors that influence the ability of a passenger to successfully jettison a Sikorsky S92 helicopter push-out
window under simulated conditions. The results clearly indicated that the technique used to jettison the
window plays a significant role in success rates. It was also noted that the location at which the strike
was applied significantly changed the force that could be applied. Given these results, it is possible that
prior to each flight offshore, passengers could physically demonstrate their capacity to open a high
physical fidelity (i.e., requires the same applied loads to jettison as those in the actual helicopter)
simulated exit.
... In a 2015 Safety Directive, the CAA provided minimum size guidelines and the instruction that the window opening be "rapid and obvious" and require no more than a "simple action" to jettison (CAA, 2015 The purpose of this study was to provide information related to the effect of push-out load and impulse on the success of jettisoning a simulated in-cabin push-out window. To date, only two studies, Taber et al., (2017b) and Taber and Sweeney (2014) have addressed this question and highlight the fact that there is a considerable knowledge gap related to the jettison task that occurs under both dry and wet conditions. ...
... Anthropometric data for this study revealed that male participants were significantly different from their female counterparts related to stature, mass, shoulder breath, seated height and functional reach (see Taber et al., 2017b for further detail). Table 4 provides detailed anthropometric information for all 50 participants who completed the dry test session. ...
... , and significantly greater mass (F = 9.20, df = 1, p = .004). However, as reported by Taber et al. (2017b), although significant morphology difference existed between male and female participants, their success rates were not significantly affected for the eight trials analyzed in this paper. ...
To address a gap in the collective knowledge base related to Helicopter Underwater Egress Training, this study examined the effectiveness of two typical strike techniques used to jettison a simulated Sikorsky S92 push-out window. Previous research has indicated that the jettison task may not be as straight forward as suggested by the “strike any corner” decals placed in corners of the push-out windows of the actual S92 helicopter. This study analyzed data provided from a larger study on the jettison task to determine how striking the simulated window with either the hand or elbow influenced the load and impulse which were generated as well as the likelihood of jettison success. Testing occurred in wet and dry conditions. Analysis of the data suggested that an elbow strike is highly successful while inverted underwater. The data also suggest that despite the difference between the hand and elbow strike success rate, the production of load between the wet and dry conditions for this type of strike was non-significant.
... Furthermore, Bartnicka et al. (2017) examined the motions of orthopedists and medical staff to improve ergonomic working conditions. Taber, Sweeney, Bishop, and Boute (2017) used Captiv to measure the movements of limb, torso, and head to jettison a helicopter push-out window. In another study, Vignais, Bernard, Touvenot, and Sagot (2017) established a continuous RULA computation by supplying a biomechanical model with motion data from Captiv. ...
Motion capturing is a promising method to assess postures and human movements and, therewith, the risk of musculoskeletal injuries that could occur while performing manual tasks in industrial settings. To obtain a reliable risk assessment, the motion capture system used has to accurately measure body postures adopted by the worker during the task. This study evaluates the accuracy of two different motion capture systems, namely the Microsoft Kinect V2 and the Captiv system, for angles of upper extremities. For this purpose, an experimental study was conducted involving 12 subjects performing preset static postures and basic movements of the upper extremities, including elbow flexion, shoulder flexion and shoulder abduction. In addition, to examine whether self-occlusion or occlusion of body parts by work equipment has an impact on the accuracy of the Kinect V2, the subjects handled boxes during some of the tests. As a gold standard, a goniometer for static and an angle scale for dynamic exercises was used. The Captiv system shows high correlation coefficients (r > 0.93) and small mean absolute errors (< 5°) for all movements except for elbow flexion. The Kinect V2 has sufficient results for joint angles captured without occlusion as well, but the accuracy significantly decreases when occlusion occurs.
This project aimed to evaluate effects of ambient lighting during practice and performance of simulated helicopter escape sequences. Participants were randomized to one of the following groups to practice a standard helicopter underwater escape sequence: Light (with room lights on), Dark (with room lights off), or Graduated (in the light for the first half and then in the dark for the second half of the trials). Following practice, participants had a minimum of thirty minutes break, followed by retention testing in the dark and then in the light. Dependent measures included accuracy and movement time. Results indicated that participants performed more accurately during the dark retention trial than during the light retention trial. This could be due to increased arousal elicited by performance in the dark or, alternatively, may suggest that performance of helicopter escape sequences is not visually mediated. Based on findings, it appears that training in the light is suitable for potential performance in the dark.
The aim of all education is to apply what we learn in different contexts and to recognise and extend this learning to new situations. Virtual learning environments can be used to build skills. Recent research in cognitive psychology and education has shown that acquisitions are linked to the initial context. This provides a challenge for virtual reality in education or training. A brief overview of transfer issues highlights five main ideas: (1) the type of transfer enables the virtual environment (VE) to be clas- sified according to what is learned; (2) the transfer process can create conditions within the VE to facilitate transfer of learning; (3) specific features of VR must match and comply with transfer of learning; (4) transfer can be used to assess a VE's effectiveness; and (5) future research on transfer of learning must examine the singular context of learning. This paper discusses how new perspectives in cognitive psychology influence and promote transfer of learning through the use of VEs.
The authors describe the effects of practice conditions in motor learning (e.g., contextual interference, knowledge of results) within the constraints of 2 experimental variables: skill level and task difficulty. They use a research framework to conceptualize the interaction of those variables on the basis of concepts from information theory and information processing. The fundamental idea is that motor tasks represent different challenges for performers of different abilities. The authors propose that learning is related to the information arising from performance, which should be optimized along functions relating the difficulty of the task to the skill level of the performer. Specific testable hypotheses arising from the framework are also described.
This chapter outlines the current understanding of how fidelity (physical, functional, and cognitive) influences helicopter underwater egress training (HUET). The distinction between the three constructs is used to consider implications of how offshore personnel are currently training in egress from a wide variety of simulators located around the globe. The discussion is framed by exploring contextual interference as it relates to skill acquisition and retention. Interior helicopter cabin configuration factors such as seating arrangements, exit positions, the use of crash-attenuating seats with four-point harnesses, and the forces required to open a simulated cabin exit are discussed as they relate to survivability and egress difficulties. Finally, this chapter considers the influence of simulation fidelity in training on the capability to predict future HUET performance in an actual helicopter ditching.
Testing of offshore helicopter seat harnesses (S76 and AW 139) was completed in realistic conditions to identify possible differences between underwater egress training harnesses and those used in actual helicopters. A weighted manikin (210lbs) was used in 24 dry trials, and four qualified instructors completed 34 underwater egress trials. Of the 58 trials, there were no (0%) release mechanism malfunctions. There were five trials (9%) in which the harness release mechanism did not full disengage on the first attempt; however all five cases (100%) resulted when the harnesses were not fully tightened correctly or when the legs of the manikin created excessive friction against the release mechanism. Results clearly showed that even in the most extreme situation (90˚ unbalanced load of 210 lbs), the harnesses were capable of opening with only minimal force. It is recommended, however, that individuals tighten their seat harness prior to critical phases of flight.
Representative samples of offshore workers engaged in the use of totally enclosed lifeboats were recruited in two different regions of Atlantic Canada for this study. Body mass, height and three selected anthropometric dimensions were measured with and without the presence of an immersion suit. Statistical comparisons were made between the two groups and to the main criteria values for body weight and space allocation used international standards for lifeboat capacity rating. There was no difference in the height, body mass and BMI values between the two groups. Both groups were found to be considerably heavier than the IMO Life Saving Code standard of 75 kg. Not surprisingly, the shoulder breadths measurements were always greater than the hip breadth measurements. The seat pan allocation of 430 mm was found to be inadequate for this population and needs to be increased. Finally, the wearing of an immersion suit increases the physical size of each subject by substantial amounts. The magnitude of increase is related to the type of suit and whether there was external compression applied during the measurement. It was recommended that the international standard should be altered by reducing the lifeboat capacity ratings by 20%.
This paper outlines the first known examination of the forces required to jettison a simulated exit used
during helicopter underwater egress training (HUET). To capture the forces placed on the simulated cabin
exit, a purpose build force plate was designed to replace an existing simulator exit used during HUET. A
25-point map was created to identify specific jettison forces required across the entire exit surface. Ten
participants completed a total of 120 underwater egress sequences ineair and in-water from a normal
flight and fully compressed crash attenuating seat position. The results indicate that the force required to
jettison the simulated exit is significantly different in relationship to location on the exit surface. From
the results, it can be concluded that helicopter underwater egress training protocols should ensure that
offshore candidates are informed of the different force requirements as well as have the opportunity to
practice jettisoning a high physical fidelity exit from a fully compressed crash attenuating seat.
Much has been made in the recent medical education literature of the incorrect characterization of simulation along a continuum of low to high fidelity (Cook et al. JAMA 306(9): 978-988, 2011; Norman et al. Med Educ 46(7): 636-647, 2012; Teteris et al. Adv Health Sci Educ 17(1): 137-144, 2012). For the most part, the common definition within the medical education community has been that simulations that present highly realistic performance characteristics, contexts, and scenarios are referred to as high-fidelity, while simulations that reduce to-be-learned skills to simpler constructs or constituent parts are referred to as low-fidelity. The issue with this is that highly-realistic has tended to mean the degree to which the simulation looks like the criterion context with little regard for what features of the simulation are in fact relevant to the skill that the educator hopes to teach. The inherent assumption that high fidelity simulations lead to better learning-an assumption for which there is a lack of supporting evidence (Norman et al. Med Educ 46(7): 636-647, 2012)-only exacerbates the problem. So much so that some have suggested that the term be abandoned all together (Hamstra et al. Acad Med J Assoc Am Med Coll 2014). While, it is true that fidelity and its importance are misconstrued in the medical education literature, the construct, defined classically as the degree of faithfulness that exists between two entities, is still fundamental to understanding the effectiveness that any one simulation might have in preparing learners for clinical performance. However, the concept of simulation fidelity must be recast in terms of the fundamental information processing events that underpin human performance.
In an effort to explore influencing factors related to survival, the following paper outlines an argument to incorporate more realistic simulator fidelity, contextual interference (CI), and skill acquisition during helicopter underwater egress training for the offshore oil and gas industry. Previous skill acquisition research is used to frame specific forms of training while highlighting the differences in current methodological approaches that may influence survival following a ditching. By examining distinct domains, a discussion of fidelity (physical and cognitive) and CI (i.e., making the training more memorable by increasing the difficulty and variability of tasks in a random order) is grounded in performance outcomes from real-world helicopter ditchings reports from 2000 to 2011. Based on the ditching event evidence gained from 97 accident reports, recommendations are made for increasing the level of fidelity and CI during this specialized emergency response training program. The accident reports are also used to develop a list of tasks that should be completed in three distinct phases of an event and should be considered in the preparation of offshore workers for a real-world ditching.
When oil and gas operators send personnel on occupationally required survival training programs, there
is an expectation that the individuals will successfully complete the course requirements and become
part of the offshore workforce. Based on current course requirements for helicopter underwater egress,
it is not surprising that pass rates are reported as being nearly 100%. However, with such a high success
rate, can there be a reasonable prediction of survival in a real helicopter ditching. This paper outlines the
current course requirement, performance outcomes for 162 individuals completing five different underwater
courses, and an argument for modifying the evaluation of successful course completion. The results
from helicopter underwater egress training (HUET) performance data collected from four international
training providers indicates that there was an overall success rate greater than 99% across egress trials
regardless of course training provider. Within a smaller dataset the results revealed that there was a total
of 32 failed attempts across 648 individual egress trials. Based on the findings it is recommended that a
critical examination of HUET programs focus on skill acquisition and retention to ensure that offshore
workforces are adequately prepared in the event of an actual helicopter ditching.
While the ultimate goal of simulation training is to enhance learning, cost-effectiveness is a critical factor. Research that compares simulation training in terms of educational- and cost-effectiveness will lead to better-informed curricular decisions. Using previously published data we conducted a cost-effectiveness analysis of three simulation-based programs. Medical students (n = 15 per group) practiced in one of three 2-h intravenous catheterization skills training programs: low-fidelity (virtual reality), high-fidelity (mannequin), or progressive (consisting of virtual reality, task trainer, and mannequin simulator). One week later, all performed a transfer test on a hybrid simulation (standardized patient with a task trainer). We used a net benefit regression model to identify the most cost-effective training program via paired comparisons. We also created a cost-effectiveness acceptability curve to visually represent the probability that one program is more cost-effective when compared to its comparator at various 'willingness-to-pay' values. We conducted separate analyses for implementation and total costs. The results showed that the progressive program had the highest total cost (p < 0.001) whereas the high-fidelity program had the highest implementation cost (p < 0.001). While the most cost-effective program depended on the decision makers' willingness-to-pay value, the progressive training program was generally most educationally- and cost-effective. Our analyses suggest that a progressive program that strategically combines simulation modalities provides a cost-effective solution. More generally, we have introduced how a cost-effectiveness analysis may be applied to simulation training; a method that medical educators may use to investment decisions (e.g., purchasing cost-effective and educationally sound simulators).
Medical Education 2012: 46: 447–453
Objectives The current paper describes a model of learning that has been used to produce efficient learning, thus yielding greater retention of information and superior performance under stress. In this paper, the model is applied to the learning of technical skills.
Structure After a brief review of the learning–performance paradox and other relevant literature from the field of movement science, the benefits of challenge and adversity for learning are discussed in the context of a framework for learning known as the challenge point framework (CPF). The framework is based on laboratory and field studies of methods that have been shown to consistently enhance learning, and is used to model and generate insight into the relationships between practice protocols and the learning that results from them.
Application The practical application of the CPF to simulation-based medical education and training is described. Firstly, a simple conceptual model that utilises three key elements to adjust the functional difficulty of the tasks to be learned is outlined. Secondly, a number of assessment strategies that may be necessary to ensure that the trainee remains in the optimal learning zone are proposed. Thirdly, a practical example is used to demonstrate how to utilise this conceptual model to design simulation environments suitable for teaching an endotracheal intubation task to beginners and more advanced trainees.
The main intent of this paper is to introduce a new statistical procedure for testing a complete sample for normality. The test statistic is obtained by dividing the square of an appropriate linear combination of the sample order statistics by the usual symmetric estimate of variance. This ratio is both scale and origin invariant and hence the statistic is appropriate for a test of the composite hypothesis of normality. Testing for distributional assumptions in general and for normality in particular has been a major area of continuing statistical research-both theoretically and practically. A possible cause of such sustained interest is that many statistical procedures have been derived based on particular distributional assumptions-especially that of normality. Although in many cases the techniques are more robust than the assumptions underlying them, still a knowledge that the underlying assumption is incorrect may temper the use and application of the methods. Moreover, the study of a body of data with the stimulus of a distributional test may encourage consideration of, for example, normalizing transformations and the use of alternate methods such as distribution-free techniques, as well as detection of gross peculiarities such as outliers or errors. The test procedure developed in this paper is defined and some of its analytical properties described in ? 2. Operational information and tables useful in employing the test are detailed in ? 3 (which may be read independently of the rest of the paper). Some examples are given in ? 4. Section 5 consists of an extract from an empirical sampling study of the comparison of the effectiveness of various alternative tests. Discussion and concluding remarks are given in ?6. 2. THE W TEST FOR NORMALITY (COMPLETE SAMPLES) 2 1. Motivation and early work This study was initiated, in part, in an attempt to summarize formally certain indications of probability plots. In particular, could one condense departures from statistical linearity of probability plots into one or a few 'degrees of freedom' in the manner of the application of analysis of variance in regression analysis? In a probability plot, one can consider the regression of the ordered observations on the expected values of the order statistics from a standardized version of the hypothesized distribution-the plot tending to be linear if the hypothesis is true. Hence a possible method of testing the distributional assumptionis by means of an analysis of variance type procedure. Using generalized least squares (the ordered variates are correlated) linear and higher-order
To evaluate the effectiveness of a novel, simulation-based educational model rooted in scaffolding theory that capitalizes on a systematic progressive sequence of simulators that increase in realism (i.e., fidelity) and information content.
Forty-five medical students were randomly assigned to practice intravenous catheterization using high-fidelity training, low-fidelity training, or progressive training from low to mid to high fidelity. One week later, participants completed a transfer test on a standardized patient simulation. Blinded expert raters assessed participants' global clinical performance, communication, procedure documentation, and technical skills on the transfer test. Participants' management of the resources available during practice was also recorded. Data were analyzed using multivariate analysis of variance. The study was conducted in fall 2008 at the University of Toronto.
The high-fidelity group scored higher (P < .05) than the low-fidelity group on all measures except procedure documentation. The progressive group scored higher (P < .05) than other groups for documentation and global clinical performance and was equivalent to the high-fidelity group for communication and technical skills. Total practice time was greatest for the progressive group; however, this group required little practice time on the resource-intensive high-fidelity simulator.
Allowing students to progress in their practice on simulators of increasing fidelity led to superior transfer of a broad range of clinical skills. Further, this progressive group was resource-efficient, as participants concentrated on lower fidelity and lower resource-intensive simulators. It is suggested that clinical training curricula incorporate exposure to multiple simulators to maximize educational benefit and potentially save educator time.
A number of potential problems are associated with egress from the helicopter cockpit in the post-crash phase of a mishap. The purpose of this study was to identify the egress problems experienced by pilots in U.S. Navy/Marine Corp helicopter cockpits, and to propose a priority of preventive interventions.
Using Naval Safety Center data, we reviewed 1980-94 Class A helicopter mishap narratives. We identified and categorized cockpit egress problems reported by pilots. The data are described in terms of problem category, helicopter type, crash terrain, and time of day.
Of the 210 survivable mishaps, 289 egress problems were reported in 128 mishaps, 61% involved aircrew factors, 16% environmental factors, 12% were related to helicopter factors, and 11% to cockpit factors. Of the 128 mishaps, 67.5% occurred during daytime, 32.5% at night, 64% in overwater crashes, 26% over land, and 10% over flight decks. The most significant, but uncommon, injuries involved the "stroking seat."
Egress hazards can be minimized by the implementation of more intensive underwater egress training, crashworthy fuel systems, better design of cockpit exits and hatches, better restraint systems, better crashworthy seats, underwater visual aids, and more streamlined personal equipment. Engineering validation is needed before committing to suggested interventions.
There are 23 different door, hatch, and window release mechanisms identified in 35 types of helicopters that earn their living over water. There is no standardization of the mechanism within each cockpit or among helicopter types, nor is there any standardization of the location relative to the operation; whether the mechanism matches the task or in which direction the door/hatch/window is jettisoned. New regulations are needed by military and civilian authorities to address the ergonomic confusion.
Testimony to the Offshore Helicopter Safety Inquiry
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Prepared for the Offshore Helicopter Safety Inquiry
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Investigation of Emergency Breathing Apparatus Skill Set Knowledge Transfer between Helicopter Underwater Escape Training Simulators. Unpublished technical document for Survival Systems Training Limited
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