Content uploaded by Osita Ugwueze
Author content
All content in this area was uploaded by Osita Ugwueze on Jan 22, 2023
Content may be subject to copyright.
1
Trends in eVTOL Aircraft Development: The
Concepts, Enablers and Challenges
Osita Ugwueze
1
and Thomas Statheros
2
Centre for Future Transport and Cities, Coventry University, Coventry, CV1 2TE, UK
Michael A. Bromfield
3
School of Metallurgy and Materials, University of Birmingham, Birmingham, B15 2TT, UK
Nadjim Horri
4
School of Mechanical, Aerospace and Automotive Engineering, Faculty of Engineering,
Environment & Computing, Coventry University, Coventry CV1 5FB, UK
By the second quarter of 2022, over 500 electric vertical take-off and landing (eVTOL)
aircraft concepts have been unveiled. However, less than 30% of the concepts have achieved
first flight due to the infancy of this industry. To keep track of these developments and the
emerging urban air mobility landscape, a technical research database has been developed to
categorize the concepts based on their propulsion architecture and compare them for
performance and safety metrics based on published data and independent analyses. This
paper presents the results of a study on 120 eVTOL aircraft concepts announced between 2014
and 2020. It reviews the current global eVTOL landscape and explores the technological
progress enabling the development of these aircraft. Data on global eVTOL aircraft
development show that eVTOL start-up companies are developing a majority of concepts at
68%. The USA, Europe and China account for over 70% of the concepts in development. The
intensity of public announcements of new eVTOL aircraft concepts appears to have peaked
after an exponential rise in the number of concepts unveiled between 2016 and 2018. This
study intends to inform readers about the trends in eVTOL development and the dominant
concepts that may be considered in trade studies.
Nomenclature
AAM
=
Advanced Air Mobility
CT
=
Combined Thrust
DEP
=
Distributed Electric Propulsion
EASA
=
European Union Aviation Safety Agency
ER
=
Electric Rotorcraft
ESC
=
Electronic Speed Controller
eVTOL
=
electric Vertical Take-Off and Landing
IT
=
Independent Thrust
LC
=
Lift + Cruise
LTU
=
Lift/Thrust Unit
MC
=
Multicopter
1
Ph.D. Research Student, AIAA Student Member
2
Assistant Professor in Aerospace Engineering
3
Associate Professor in Aerospace Engineering, AIAA Member
4
Assistant Professor in Aerospace Engineering, AIAA Member
2
PAV
=
Personal Aerial Vehicle
PL
=
Powered Lift
SRW
=
(Electric) Autogyro
TB
=
Tilt Body
TF
=
Tilt Fan
TP
=
Tilt Prop
TW
=
Tilt Wing
UAM
=
Urban Air Mobility
UAV
=
Unmanned Aerial Vehicles
V/STOL
=
Vertical and/or Short Take-off and Landing aircraft
VT
=
Vectored Thrust
W
=
Wingless
I. Introduction
The number of electric vertical take-off and landing (eVTOL) aircraft concepts, prototypes, and production
vehicles has recently grown to over 500 [1]. This significant growth is reminiscent of the early development of
powered flight, where engineers, entrepreneurs and amateurs attempted to design, build and fly the world’s first
powered aircraft. Improvements in battery technologies, electric motors and power management systems driven by
the automotive industry and the need for green energy solutions enable electric-powered flight and have resulted in a
proliferation of vehicles [2]. These proposed vehicles are capable of vertical take-off and landing (VTOL), are fully
electric or hybrid-powered propulsion and energy storage systems, are typically designed to carry under ten passengers
and are expected to have a take-off mass under 3,175 kg [3]. These eVTOL aircraft are believed to be the cumulative
result of technological disruptions in energy storage [4], advancements in distributed electric propulsion (DEP)
technologies [5], regulatory receptiveness [3, 6], advances in simplified vehicle operations and flight controls [7, 8]
and the general progress in autonomous navigation [9].
Increasing urbanization and rapid growth of population centers continue to intensify the strain on the inhabitants’
lives. Nowhere are these effects more noticeable than in traffic congestion and air pollution. As the impacts of climate
change become more apparent, there is a growing consensus amongst industry leaders, researchers and governments
regarding the need for clean and sustainable transport solutions for the cities of the future. A proposed concept to
tackle this issue is urban air mobility (UAM). The National Aeronautics and Space Administration (NASA) outlines
UAM as a concept which enables safe and efficient air operations in a metropolitan area for person-carrying and
unhabituated aircraft systems [10]. A significant proportion of eVTOL aircraft is designed to provide UAM solutions.
In addition, there are also numerous designs for personal aerial vehicles (PAV). Aircraft for both use cases are within
the sphere of advanced air mobility (AAM) vehicles [11].
The air taxi mission is a typical UAM mission [12]. Air taxi missions may cover intra-city routes up to 50 km in
the short term, then up to 100 km in the medium term and then inter-city routes with significantly greater distances in
the long term [2, 10]. For example, a short-range inter-city UAM mission will be sufficient for a trip from the financial
center of London to London Heathrow Airport. In contrast, a future long-range UAM mission can see routes like
London to Birmingham. This is a 200 km trip that is too short for a commercial flight but could benefit from reduced
travel times compared with similar rail travel on the same route. Inter-city missions that cover 100+ km are heavily
dependent on progress in battery density technology levels for battery-powered concepts. The use of hybrid-electric
propulsion in some concepts is a stop-gap solution to this energy density problem until the technological maturity and
economic feasibility of fully electric battery-powered concepts are realized. There are ever-increasing potential use
cases for eVTOL aircraft. Public and emergency services such as policing, firefighting, air ambulance and surveillance
are among potential applications of eVTOL aircraft [13]. Other applications, such as corporate activities, logistics,
entertainment, remote healthcare and agriculture, have also been identified [10].
This paper presents select trends in eVTOL aircraft development based on a study of 120 eVTOL aircraft concepts
announced between 2014 and 2022. The concepts are categorized by their propulsion configurations, presented
graphically in the paper’s main sections, and listed in the appendix. The following sub-sections discuss the concept of
distributed electric propulsion and its apparent benefits for eVTOL aircraft design. Progress in the eVTOL aircraft
certification process in Europe is also covered. An overview of the different eVTOL aircraft classes and their
propulsion configurations is presented in the following section. Finally, key trends in the global development of
eVTOL aircraft are presented and discussed.
3
A. Distributed Electric Propulsion
Advances in energy storage technologies, electric motor capabilities and power distribution have enabled the
concept of distributed electric propulsion [14-16]. DEP is likely to solve two challenging problems that have plagued
conventional Vertical/Short Take-off and Landing Aircraft (V/STOL). These problems, power distribution and
control, have hindered the maturity of VTOL aircraft. As a result, there has only been a handful of successful
conventional V/STOL aircraft. These include the commonly known BAE Systems Harrier Jump Jet [17], its relatively
new successor, the Lockheed Martin F-35 Lightning [18], the Boeing V-22 Osprey [19] and the most recent
development, the Leonardo Helicopters AW609 tiltrotor [20]. The last two types are transport aircraft as opposed to
the first two, which are fighter aircraft. These aircraft have stemmed from several years of development and are well-
known for the time it has taken to develop and certify them. The common theme of extended development and
certification times exemplifies the complexity of the conventional VTOL aircraft type.
The leading cause of the power distribution problem in conventional VTOL aircraft is using one or two jet engines
to power and control the aircraft [21, 22]. Therefore, it becomes an engineering challenge to distribute this power to
balance the aircraft in hover flight. DEP offers to solve this challenge by utilizing several smaller electric motors
placed strategically around the aircraft to naturally balance the aircraft during hover or at least make the balancing
problem significantly easier for flight control systems to augment. The controllability of eVTOL aircraft in hover
mode has also been an issue for conventional VTOL aircraft because of the high moment forces expanded by the
engine ducts. With DEP, it is possible to go around this problem by utilizing only a portion of the motors, those placed
at the extremities of the eVTOL aircraft, for control. These are usually the end motors on either wing (lateral control
or roll) or motors placed at the fore and aft of the aircraft (longitudinal control or pitch). At the same time, the majority
of the motors remain to provide power. Also, due to the smaller mass of these motors, they have a higher impulse and
smaller output force. This is advantageous for better response times in roll and pitch rates. It also allows for finer
refinements in the aircraft’s attitude control, especially during hover. Therefore, the controllability of eVTOL aircraft,
especially in the hover phase, would need to be significantly less complex than that of conventional VTOL aircraft.
The advantages of DEP, outlined so far, have considerably reduced the development complexity for eVTOL aircraft
because the power distribution and control problem can be solved by incorporating DEP into the aircraft design. Thus
there is a lower requirement for engineering resources to be devoted to developing an eVTOL aircraft. This has enabled
the proliferation of several concepts by many eVTOL developers globally.
B. eVTOL Certification Efforts
Several manufacturers actively compete to be among the first to enter the eVTOL aircraft type into service. This
is predictable as the projected global market size for UAM is estimated to exceed 80 billion dollars by 2035 [23].
Consequently, eVTOL aircraft developers are perceived to be tight-lipped in their design specifications and processes.
These are seen as trade secrets currently because these aircraft are in a new category. However, it is expected that
some of the proprietary design solutions, methodologies and innovative technologies employed in some proposed
designs could be the determining factor for commercial success if proven. For this reason, eVTOL aircraft developers
will likely continue developing their concepts in secrecy to preserve their competitive advantage.
By the end of 2022, over 500 eVTOL aircraft concepts were publicly unveiled. These designs vary widely but aim
to address the same problem – achieving reliable and efficient electric VTOL capability. There is currently an absence
of certification specifications for eVTOL aircraft due to its infancy. However, the initial reception from regulatory
agencies has been positive. The European Union Aviation Safety Agency (EASA) published its proposed special
condition for small-category VTOL aircraft in 2018 [24]. This was followed by a revised publication in July 2019 [3].
This document is not a full aircraft certification specification but a proposed means of compliance based on
consultations with eVTOL developers. The document addresses the definition of eVTOL aircraft, the uniqueness of
their distributed propulsion configuration, and attempts to prescribe airworthiness standards to issue a type certificate
for these aircraft [3]. Initial conditions set out by the document include the requirement for these aircraft is a vertical
take-off and landing capability. EASA also expects these aircraft types to utilize fully electric or hybrid-powered
propulsion and energy storage systems and be typically designed to carry under ten passengers with a maximum take-
off mass below 3,175 kg [3]. EASA has progressed on this by soliciting commentaries from eVTOL experts in industry
and academia via its Comment-Response Tool (CRT). Finally, the need for a comprehensive aircraft safety analysis
cannot be understated, given the relatively unfamiliar territory defined by eVTOL aircraft operating urban air mobility
missions. Therefore, proactive safety approaches in hazard identification would be necessary to sustain or surpass
current safety levels in commercial and civil aviation. Established safety analysis tools such as functional hazard
analysis and failure modes and effects analysis have proved beneficial for aircraft safety analysis [25].
4
II. eVTOL Aircraft Architecture and Concepts
EASA, via its Special Condition for small-category VTOL aircraft [3], has outlined two distinct characteristics
common to eVTOL aircraft. These are vertical take-off and landing (VTOL) capability and a distributed electric
propulsion system [3]. The latter allows for less complicated implementations of propulsion systems for the vertical
lift and forward thrust mode compared to jet engines and the complex thrust vectoring schemes employed by
conventional VTOL aircraft. Subsequently, these propulsion units will be referred to as lift/thrust units (LTUs), in line
with the EASA SC-VTOL nomenclature [3]. EASA establishes that the VTOL capability of these aircraft sufficiently
differentiates them from conventional aircraft. Likewise, electric propulsion systems (of more than two LTUs) also
adequately differentiate eVTOL aircraft from conventional rotorcraft [3, 26].
Figure 1. Propulsion architectures of eVTOL aircraft
A. Powered Lift eVTOL
All eVTOL aircraft can take-off and land vertically, thus requiring no need for a runway. However, only powered
lift aircraft utilize wings (Figure 1). This allows them to cruise at similar speeds to conventional fixed-wing aircraft,
a significantly higher altitude than wingless eVTOL aircraft and helicopters. This extra ability of powered lift aircraft
naturally presents opportunities to carry out more extended-range missions more efficiently than the wingless type.
Thus, allowing the aircraft designer flexibility to exceed the capabilities of wingless in terms of cruise speed, payload,
and range. However, the advantages do come at a cost. Powered lift aircraft are significantly more complex to design.
This is mainly due to two factors:
• The addition of a wing and its associated systems for aerodynamic lift during the cruise stage and
• the additional LTUs required for the forward mode and, in some cases, their associated vectoring systems.
The independent thrust eVTOL type entails separate propulsion for forward thrust during the cruise phase, while
the LTUs for forward lift remain inactive. These LTUs are considered deadweight when inactive, directly contributing
to increased drag and overall aircraft mass. eVTOL aircraft designers mitigate the drag issue by locking propellers
parallel to the slipstream during cruise [27, 28]. While other designs feature stowing the unused vertical lift LTUs in
aerodynamic pods or nacelles during cruise [29]. However, even incorporating this feature would add to the overall
design complexity. The Wisk eVTOL (Figure 2b) exemplifies the independent thrust concept with its separate LTU
for forward flight.
5
(a) Joby Aviation eVTOL [30]
(b) Wisk Generation 5 [28]
(c) Vertical Aerospace VX-4 [31]
Figure 2. Powered lift eVTOL aircraft (a) Vectored Thrust (b) Independent Thrust (c) Combined Thrust
The vectored thrust types appear to have the most complexity, mainly due to the systems required for vectoring
thrust between the vertical and forward regimes. This problem is not new, as it has existed since the early development
of conventional VTOL aircraft in the 1960s [32]. As a result, many approaches for thrust vectoring have been
developed over time and are now being adapted to eVTOL aircraft designs. Tilt fan and tilt prop designs rotate only
the propulsion units, in this case, lift fans like the Lilium eVTOL [33] or propellers like the Joby eVTOL [34]. Rotating
these propulsion units activate the vertical lift or forward thrust modes. The Joby Aviation eVTOL (Figure 2a) is an
example of the vectored thrust and tilt prop categories, with all its LTUs utilized for forward and hover flight modes.
Finally, the combined thrust type design incorporates thrust vectoring for some propulsion units while the
remaining units are fixed for the vertical mode. The advantage of this type lies in the fact that it lessens the deadweight
problem seen in the independent thrust type because all the propulsion units are used during vertical mode while the
unused propulsion units are parked during the forward mode. An example of this design is the Vertical Aerospace
VX4 [31] (Figure 2c).
B. Wingless eVTOL
Wingless eVTOL aircraft rely solely on the thrust from their lift/thrust units for both vertical lift and forward flight.
Multicopters, as the name suggests, possess multiple LTUs which can only provide vertical lift, akin to a helicopter.
(a) Volocopter VoloCity [35]
(b) Jaunt Air Mobility [36]
Figure 3. Wingless eVTOL aircraft (a) Multicopter (b) Electric Rotorcraft
6
The multicopter type is the dominant secondary classification of wingless architecture. The VoloCity by
Volocopter is a two-seat multicopter with 18 LTUs (Figure 3a). There are also electric helicopter eVTOL concepts.
Some of these concepts contain additional LTUs for increased speed in forward flight (Figure 3b). Nevertheless, their
behavior in flight remains closer to a helicopter than a fixed-wing aircraft. Many of the multicopter concepts proposed
are designed mainly for use in air taxi services and emergency services. Personal Aerial Vehicles (PAV), although
technically possessing a multicopter architecture, distinguish themselves from the previous subclass in carrying
capacity. PAVs are usually single-seat eVTOL aircraft geared towards personal use, with some concepts capable of
both ground-based transport mode and flight mode [37]. As the name suggests, PAVs are single-seat multicopter
eVTOLs where the operator sits or stands to ride the aircraft. These aircraft are generally observed to be enthusiast
vehicles with significantly lower utility when compared to multicopters. In addition, due to the low cost of off-the-
shelf electric motors required in powering this weight class, PAVs are generally the least expensive to manufacture.
For this reason, larger and more complex eVTOL designs usually start as PAVs until the propulsion architecture can
be proven.
III. Development Trends
A technical research database has been developed to keep track of developments in eVTOL aircraft design and
UAM [38]. A selection of the aircraft parameters is presented in the appendix section. In addition, 120 eVTOL aircraft
concepts were assessed and categorized in the database. Data on the development of the concepts were collected from
the developers’ websites, press releases and articles from the Electric VTOL News website, run by the Vertical Flight
Society [1]. This section presents a selection of data and metrics to provide insight into the development of eVTOL
aircraft worldwide.
Figure 4. Overview of design maturities of eVTOL aircraft concepts between 2018 and 2020
In 2018, 7% of eVTOL aircraft achieved their first flight. However, this significantly improved by early 2020, as
28% of eVTOL aircraft had now achieved their first flight (Figure 4). These flights include the first flights of sub-
scale and full-scale eVTOL aircraft prototypes in addition to piloted first flights. The increase in the number of first
flights over the time period shows that eVTOL aircraft development is still in its infancy since over 70% of aircraft in
development have not yet reached the flight-testing stage. Most of these flights occurred with wingless aircraft, 4% in
2018 and 22% by 2020, suggesting that the powered lift type development is indeed more complicated than wingless
aircraft in practice. It can also be observed that most defunct aircraft are of the wingless eVTOL aircraft type. This
suggests that the wingless aircraft may primarily be used to explore the business case and technological feasibility of
an eVTOL aircraft concept before a go-to-market version is developed, which is more likely to be a powered lift
eVTOL aircraft type.
One hundred and twenty eVTOL concepts were classified based on their propulsion configurations and presented
in Figure 5. The methodology used to classify the eVTOL aircraft concepts by their propulsion configurations was
7
adapted from the V/STOL Wheel in Ref. [39], which was initially developed by McDonell Aircraft in the 1960s [39].
A list of these aircraft and their key characteristics is also presented in the Appendix.
Figure 5. eVTOL Wheel – The classification of eVTOL aircraft concepts by their propulsion configuration
From the aircraft categorized so far, the powered lift eVTOL aircraft account for 57% with 68 aircraft. The
wingless aircraft take the remaining 43% at 52 aircraft. The vectored thrust subfamily takes up 53% of the powered
lift category with 36 aircraft. The independent thrust is at 30% with 21 aircraft, and the combined thrust takes up the
remaining 17% with 11 aircraft. In the wingless eVTOL aircraft category, multicopters constitute 92% of the group
with 48 aircraft. Electric rotorcraft take up the remaining 8% at 4 aircraft.
Examining the global development of eVTOL aircraft in Figure 6, the USA tops the list, commanding almost half
of the global development efforts at 41%. The UK comes in second with a share of 12% of global vehicles in
development. The USA, UK, Europe, China, and Russia account for over 70% of the global eVTOL aircraft
development market. The majority of the companies developing eVTOL aircraft are start-ups at 68%. eVTOL aircraft
development among major aircraft manufacturers like Boeing, Airbus and Embraer are split equally, with relatively
smaller aircraft manufacturers like Pipistrel Aerospace at 8% each. Concepts in development by research institutes
8
and universities account for 6% collectively. Finally, automotive manufacturers looking to diversify their offerings
account for about 2%, while the remaining concepts are linked to individual enthusiasts.
Figure 6. Global share of eVTOL aircraft development between 2014 and 2020
Figure 7 shows the cumulative announcements of eVTOL aircraft concepts over time. Initial hype for these aircraft
types can be observed in the exponential increase from the end of 2016 to 2018. There were also significant jumps in
announcements during the Uber Elevate summits in 2017, 2018 and 2019 as eVTOL developers used the opportunity
to announce their concepts and prototypes publicly. However, it appears that expectations are beginning to peak as
the intensity of announcements appears to subside while the eVTOL aircraft development industry converges to
maturity.
Figure 7. Cumulative announcements of eVTOL aircraft concepts from 2014 to 2019
9
IV. Conclusion
An exposition of the eVTOL aircraft development landscape has been presented in this paper. First, the different
eVTOL types were reviewed. The main categories identified are powered lift and wingless eVTOL aircraft types. The
former encapsulates all eVTOL concepts that can generate most of their aerodynamic lift in forward flight via the
wing. While the latter are incapable of this because, as their name suggests, they do not employ wings for sustenance
but rather downward thrust. The wingless eVTOL aircraft, although having a simpler architecture, performs poorly in
cruise mode due to its lack of aerodynamic lift in forward flight. However, due to its apparent simplicity, the type
appears to be the go-to choice for initial assessment and feasibility studies for eVTOL aircraft developers before a go-
to-market version, likely now the powered lift type, is then developed from the initial wingless baseline.
Similar to the development of early powered aircraft in the 19th century, eVTOL aircraft design concepts are
continuously evolving and are doing so quite rapidly. Over the last five years, there has been an exponential increase
in research attention and funding for eVTOL aircraft design and UAM. A selection of data analysis on trends in
eVTOL aircraft development from 2014 to 2020 has been presented. One hundred and twenty eVTOL aircraft concepts
were assessed and categorized by their propulsion configurations. In addition, the eVTOL development landscape was
studied. The results show that the USA, UK, Europe and China accounted for over 70% of eVTOL aircraft in
development globally. The results also show that eVTOL start-up companies are developing the majority of new
concepts (68%). Finally, the intensity of public announcements of new eVTOL aircraft concepts appears to have
peaked after an exponential rise in the number of concepts unveiled between 2016 and 2018.
The eVTOL development landscape is still highly active. Thus, the results presented in this paper serve as an initial
outlook on the eVTOL aircraft development landscape. Furthermore, the data used for this study is based on published
aircraft data from several eVTOL developers, most of which are start-ups and non-traditional aerospace companies.
Many of the proposed concepts have also not been proven commercially. Thus, the eVTOL aircraft information
published by these companies should be treated with caution until widescale adoption and entry into service of these
aircraft are achieved.
Nevertheless, further analysis on the topic is ongoing. The research database is continually updated as new vehicles
are revealed, prototypes achieve their first flight, and more data is released by manufacturers, together with the results
of academic research. This study intends to inform readers about the trends in eVTOL development and the dominant
concepts that may be considered in trade studies. Which concepts will survive the test of time are still unknown, but
those that will survive will likely need to employ innovative solutions and systems to tackle the limitations of
actualizing eVTOL aircraft in the context of the pre-defined urban air mobility concept of operations.
Appendix
Table 1. eVTOL Aircraft Data
SN
Name
Developer
Country of
Development
(ISO2 [40])
Primary
Class
Secondary
Class
Tertiary
Class
1
Aptos Blue
A2-Cal
US
PL
VT
TP
2
Z-300
ACS Aviation
BR
PL
VT
TW
3
X8
Aerial Vehicle Automation
US
WL
MC
-
4
aG-4 Liberty
aeroG Aviation
US
PL
VT
TP
5
AeroMobil 5.0
AeroMobil
SK
PL
IT
LC
6
Air-One
Air
IL
PL
VT
TB
7
Genesis
Airborne Motorworks
US
WL
MC
-
8
Vahana (Alpha)
Airbus
US
PL
VT
TW
9
Vahana (Beta)
Airbus
US
PL
VT
TW
10
CityAirbus
Airbus
DE
WL
MC
-
11
Pop.Up
Airbus, Italdesign & Audi
FR
WL
MC
-
12
MOBi-One V3
AirSpaceX
US
PL
CT
TW
13
Skai
Alaka’i Technologies
US
WL
MC
-
14
Airspeeder Mk4
Alauda
AU
WL
MC
-
15
Ambular 2.0
Ambular
CA
WL
MC
-
16
Vertiia
AMSL Aero
AU
PL
VT
TW
17
A2-Cal
Aptos Blue
US
PL
CT
TP
18
Midnight
Archer
US
PL
VT
TP
10
19
Maker
Archer
US
PL
VT
TP
20
Atea
Ascendance Flight Technologies
FR
PL
IT
LC
21
Volante Vision
Aston Martin
GB
PL
CT
TP
22
Elroy
Astro Aerospace
US
WL
MC
-
23
V600
AutoFlightX
DE
PL
IT
LC
24
Y6S
Autonomous Flight
GB
PL
CT
TF
25
Yurik
Aviation and Space Technologies
RU
WL
MC
-
26
Bartini
Bartini Aero
RU
WL
MC
-
27
Cezeri
Baykar Technologies
TR
WL
MC
-
28
Bell Nexus 4EX
Bell
US
PL
VT
TP
29
Bell Nexus 6HX
Bell
US
PL
VT
TP
30
Nexus
Bell Helicopters
US
PL
VT
TF
31
Alia-250c
Beta Technologies
US
PL
IT
LC
32
Ava XC
Beta Technologies
US
PL
VT
TP
33
Aurora PAV
Boeing
US
PL
IT
LC
34
Cargo Air Vehicle
Boeing
US
WL
MC
-
35
SkyCab
Braunwagner
DE
PL
IT
LC
36
Beccarii
B-Technology
PL
WL
MC
-
37
CAPS
CAPS
FR
WL
MC
-
38
Flying Taxi
Central Aerohydrodynamic Institute
RU
WL
MC
-
39
Mini-Bee
CollaborativeBee
FR
PL
CT
TF
40
ZeroG
Davinci Technology
US
WL
MC
-
41
ZeroG V3
Davinci Technology
US
WL
MC
-
42
DR-7
Delorean Aerospace
US
PL
VT
TF
43
Big Drone
Drone Champions AG
LI
WL
MC
-
44
aEro 2
Dufour Aerospace
CH
PL
VT
TW
45
aEro 3
Dufour Aerospace
FR
PL
VT
TP
46
EHang 116
Ehang
CN
WL
MC
-
47
EHang 184
Ehang
CN
WL
MC
-
48
Ehang 216
Ehang
CN
WL
MC
-
49
Whisper
Electric Aircraft Concept
FR
WL
MC
-
50
X01
Electric Visionary Aircrafts
FR
PL
CT
TF
51
Flexcraft
Embraer & Flexcraft Consortium
PT
PL
IT
LC
52
Lancer Epav
Esprit Aeronautics
GB
PL
IT
LC
53
Eve V3
Eve Air Mobility
BR
PL
IT
LC
54
Flutr
Flutr Motors
DE
WL
MC
-
55
PAC VTOL 420-120
Flyter
RU
PL
IT
LC
56
PAC VTOL 720-200
Flyter
RU
PL
IT
LC
57
Frogs 282
Frogs Indonesia
ID
WL
MC
-
58
KiiRA
Garudeus Aviation
US
WL
MC
-
59
Tusi Technology Demonstrator
Gelisim University
TR
WL
MC
-
60
Koncepto Millenya
Gravity X
PH
WL
MC
-
61
Gatri
Green Aerotechnics Research Institute
CN
WL
MC
-
62
S700
Hi-Fly
RU
WL
MC
-
63
Venturi
HopFlyt
US
PL
VT
TW
64
Formula 2 Prototype
Hover
RU
WL
MC
-
65
Scorpion Air Taxi
Hover
RU
WL
MC
-
66
Drone Taxi R-1
Hoversurf
US
PL
IT
LC
67
Technology Demonstrator
International Aviation Center
RU
WL
MC
-
68
Jaunt
Jaunt Air Mobility
US
WL
SRW
-
69
J2000
Jetoptera
US
PL
VT
TF
70
Joby
Joby Aviation
US
PL
VT
TW
71
S4
Joby Aviation
US
PL
VT
TP
72
Butterfly
Karem Aircraft
US
PL
VT
TP
73
OPPAV
KARI
KR
PL
CT
TP
74
Cora
Kitty Hawk
US
PL
IT
LC
75
Flyer
Kitty Hawk
US
WL
MC
-
76
Optionally Piloted PAV
Korea Aerospace Research Institute
KR
PL
VT
TP
77
Element Drone
Kovacs
HU
WL
MC
-
78
Heavy Duty Drone
Kovacs
HU
WL
MC
-
79
FD-One
Lazzarini Design Studio
IT
WL
MC
-
80
HEXA
LIFT Aircraft
US
WL
MC
-
11
81
Eagle
Lilium
DE
PL
VT
TP
82
Lilium Jet (5x)
Lilium
DE
PL
VT
TF
83
LimoConnect
Limosa
CA
PL
VT
TP
84
AIVA
Micor Technologies
US
PL
VT
TB
85
AMVA
Micor Technologies
US
PL
VT
TB
86
SureFly
Moog Inc.
US
WL
MC
-
87
MyDraco
MyDraco
UA
PL
VT
TF
88
VTOL
Napoleon Aero
RU
PL
IT
LC
89
Human Carrier Drone
Polytechnic Institute of Cambodia
KH
WL
MC
-
90
eOpter
Neoptera
GB
PL
VT
TB
91
BlackFly (V3 Intl)
Opener
US
PL
VT
TB
92
PA-890
Piasecki Aircraft
US
WL
SRW
-
93
eVTOL
Pipistrel
SI
PL
IT
LC
94
Transwing
PteroDynamics
US
PL
VT
TW
95
Ray VTOL Aircraft
Ray Research
CH
PL
IT
LC
96
eVTOL
Rolls-Royce
GB
PL
VT
TW
97
HUMA
Samad Aerospace
GB
PL
VT
TB
98
Starling Jet
Samad Aerospace
GB
PL
CT
TF
99
Cartivator
SkyDrive
JP
WL
MC
-
100
SD-03
SkyDrive
JP
WL
MC
-
101
SD-XX
SkyDrive
JP
WL
MC
-
102
TF-2-LPP
Terrafugia
US
PL
IT
LC
103
TF-X
Terrafugia
US
PL
VT
TP
104
FlyKart 2
Trek Aerospace
US
WL
MC
-
105
Esinti
Turkish Technic
TR
WL
MC
-
106
eCRM-001
Uber
US
PL
CT
TP
107
eCRM-002
Uber
US
PL
IT
LC
108
eCRM-003
Uber
US
PL
IT
LC
109
Personal Air Taxi 200
VerdeGo Aero
US
PL
VT
TW
110
VX-4
Vertical Aerospace
GB
PL
CT
TP
111
AAV Vimana
Vimana Global
US
PL
VT
TW
112
VoloCity
Volocopter
DE
WL
MC
-
113
Volocopter 2X Prototype
Volocopter
DE
WL
MC
-
114
VoloDrone
Volocopter
DE
WL
MC
-
115
NeoXcraft
VRCO
GB
WL
MC
-
116
Generation 6
Wisk
US
PL
IT
LC
117
Voyager X2
XPeng
CN
WL
MC
-
118
Trifan 600
XTI Aviation
US
PL
CT
TF
119
EOPA
Zenith Altitude
CA
PL
VT
TW
120
Zuri
Zuri
CZ
PL
IT
LC
References
[1] The Electric VTOL News by the Vertical Flight Society, "eVTOL Aircraft Directory," url: http://evtol.news/aircraft
[retrieved 30 May 2022].
[2] Datta, A., "Commercial Intra-City On-Demand Electric-VTOL Status of Technology." AHS/NARI Transformative Vertical
Flight Working Group-2, 2018. url: https://vtol.org/files/dmfile/TVF.WG2.YR2017draft.pdf
[3] EASA, "Special Condition for Small-category Vertical Take-Off and Landing (VTOL) Aircraft." Vol. SC-VTOL-01,
European Aviation Safety Agency, Brussels, 2019.
[4] Yu, X., Sandhu, N. S., Yang, Z., and Zheng, M., "Suitability of energy sources for automotive application – A review,"
Applied Energy Vol. 271, 2020, p. 115169.doi: 10.1016/j.apenergy.2020.115169
[5] Hepperle, M., "Electric Flight - Potential and Limitations." STO-MP-AVT-209, Institute of Aerodynamics and Flow
Technology Braunschweig, Germany, 2012. url: https://elib.dlr.de/78726/1/MP-AVT-209-09.pdf
[6] FAA, and CAA, "Joint FAA and United Kingdom CAA Statement on eVTOL Aircraft," url:
https://www.faa.gov/newsroom/joint-faa-and-united-kingdom-caa-statement-evtol-aircraft [retrieved 20 May 2022].
[7] Wing, D. J., Chancey, E. T., Politowicz, M. S., and Ballin, M. G., "Achieving Resilient In-Flight Performance for
Advanced Air Mobility through Simplified Vehicle Operations," AIAA AVIATION 2020 FORUM. 2020. doi:
10.2514/6.2020-2915
[8] Lombaerts, T., Kaneshige, J., and Feary, M., "Control Concepts for Simplified Vehicle Operations of a Quadrotor eVTOL
Vehicle," AIAA AVIATION 2020 FORUM. 2020. doi: 10.2514/6.2020-3189
12
[9] Bijjahalli, S., Sabatini, R., and Gardi, A., "Advances in intelligent and autonomous navigation systems for small UAS,"
Progress in Aerospace Sciences Vol. 115, 2020, p. 100617.doi: 10.1016/j.paerosci.2020.100617
[10] Goyal, R., Reiche, C., Fernando, C., Serrao, J., Kimmel, S., Cohen, A., and Shaheen, S., "Urban Air Mobility (UAM)
Market Study." 20190001472, National Aeronautics and Space Administration, Washington, D.C., 2018. url:
https://ntrs.nasa.gov/citations/20190001472
[11] Liu, Y., Kreimeier, M., Stumpf, E., Zhou, Y., and Liu, H., "Overview of recent endeavors on personal aerial vehicles: A
focus on the US and Europe led research activities," Progress in Aerospace Sciences Vol. 91, 2017, pp. 53-66.doi:
10.1016/j.paerosci.2017.03.001
[12] Uber Elevate, "Fast-Forwarding to the Future of On-Demand, Urban Air Transportation," url:
https://www.uber.com/elevate.pdf [retrieved June 2018].
[13] Doo, J. T., Pavel, M. D., Didey, A., Hange, C., Diller, N. P., Tsairides, M. A., Smith, M., Bennet, E., Bromfield, M., and
Mooberry, J., "NASA Electric Vertical Takeoff and Landing (eVTOL) Aircraft Technology for Public Services – A White
Paper," NASA Transformative Vertical Flight Working Group 4 (TVF4). 20205000636, National Aeronautics and Space
Administration, Washington, D.C., 2021. url: https://ntrs.nasa.gov/citations/20205000636
[14] Gnadt, A. R., Speth, R. L., Sabnis, J. S., and Barrett, S. R. H., "Technical and environmental assessment of all-electric 180-
passenger commercial aircraft," Progress in Aerospace Sciences Vol. 105, 2019, pp. 1-30.doi:
10.1016/j.paerosci.2018.11.002
[15] Thapa, N., Ram, S., Kumar, S., and Mehta, J., "All electric aircraft: A reality on its way," Materials Today: Proceedings
Vol. 43, 2021, pp. 175-182.doi: 10.1016/j.matpr.2020.11.611
[16] Staack, I., Sobron, A., and Krus, P., "The potential of full-electric aircraft for civil transportation: from the Breguet range
equation to operational aspects," CEAS Aeronautical Journal Vol. 12, No. 4, 2021, pp. 803-819.doi: 10.1007/s13272-021-
00530-w
[17] Dow, A., Pegasus, The Heart of the Harrier: The History and Development of the World's First Operational Vertical Take-
off and Landing Jet Engine: Pen & Sword Aviation, 2009.
[18] Bevilaqua, P., "Inventing the F-35 Joint Strike Fighter," 47th AIAA Aerospace Sciences Meeting including The New
Horizons Forum and Aerospace Exposition. American Institute of Aeronautics and Astronautics, Orlando, FL, 2009. doi:
10.2514/6.2009-1650
[19] McVeigh, M. A., Liu, J., O'Toole, S. J., and Woods, S., "V-22 Osprey aerodynamic development — a progress review,"
The Aeronautical Journal (1968) Vol. 101, No. 1006, 1997, pp. 231-244.doi: 10.1017/S0001924000066264
[20] Mitchell, D. G., Klyde, D. H., Shubert, M., Sizoo, D., and Schaller, R., "Testing for Certification of Urban Air Mobility
Vehicles," AIAA SCITECH 2022 Forum. American Institute of Aeronautics and Astronautics, San Diego, CA, 2022. doi:
10.2514/6.2022-0889
[21] Raymer, D. P., "The impact of VTOL on the conceptual design process," AIAA/AHS/ASEE Aircraft Design, Systems and
Operations Meeting. American Institute of Aeronautics and Astronautics, Atlanta, Georgia, 1988. doi: 10.2514/6.1988-
4479
[22] Saeed, B., and Gratton, G., "An evaluation of the historical issues associated with achieving non-helicopter V/STOL
capability and the search for the flying car," The Aeronautical Journal Vol. 114, No. 1152, 2010, pp. 91-102.doi:
10.1017/S0001924000003560
[23] BIS Research, "Urban Air Mobility (UAM) Market – A Global and Regional Analysis." SAU0702SB, BIS Research,
2021. url: https://bisresearch.com/industry-report/global-urban-air-mobility-market.html
[24] EASA, "Proposed Special Condition for small-category VTOL aircraft." Vol. SC-VTOL-01, European Aviation Safety
Agency, Brussels, 2018.
[25] Kritzinger, D., Aircraft System Safety: Assessments for Initial Airworthiness Certification: Woodhead Publishing, 2017.
doi: 10.1016/C2014-0-03961-5
[26] Ugwueze, O., Statheros, T., Horri, N., Innocente, M., and Bromfield, M., "Investigation of a Mission-based Sizing Method
for Electric VTOL Aircraft Preliminary Design," AIAA SCITECH 2022 Forum. American Institute of Aeronautics and
Astronautics, San Diego, CA, 2022. doi: 10.2514/6.2022-1931
[27] EVE, "Mobility Reimagined," url: https://eveairmobility.com [retrieved 9 May 2022].
[28] Wisk Aero, "Autonomous Urban Air Mobility," url: https://wisk.aero/aircraft [retrieved 30 November 2022].
[29] Howard, C. E., "Uber unveils third eVTOL Common Reference Model concept for future flying taxis," url:
https://www.militaryaerospace.com/commercial-aerospace/article/14229631/uber-unveils-third-evtol-common-reference-
model-concept-for-future-flying-taxis [retrieved 9 May 2022].
[30] Joby, A., "Joby," url: https://www.jobyaviation.com [retrieved 09 May 2022].
[31] Vertical Aerospace, "VX4 - Urban Air Mobility - Vertical Aerospace," url: https://vertical-aerospace.com/vx4 [retrieved
09 May 2022].
[32] AFRPS, "Introduction to V/STOL Technology." USAF Aerospace Research Pilot School, California, 1970. url:
[33] Lilium, "Lilium Jet - The First Electric VTOL (eVTOL) Jet," url: https://lilium.com/jet [retrieved.
[34] Joby Aviation, "Joby," url: https://www.jobyaviation.com [retrieved 09 May 2022].
[35] Volocopter, "Volocopter," url: https://www.volocopter.com [retrieved 3 March 2018 2018].
[36] Jaunt Air Mobility, "Jaunt Air Mobility," url: https://www.jauntairmobility.com/ [retrieved October.
13
[37] Jump, M., Padfield, G., White, M., Fua, P., Zufferey, J., Schill, F., Siegwart, R., Bouabdallah, S., Decker, M., and Schippl,
J., "myCopter: Enabling technologies for personal air transport systems," Royal Aeronautical Society Conference on the
Future Rotorcraft (RAeS 2011). Royal Aeronautical Society, London, 2011, pp. 1-15.
[38] Ugwueze, O., "eVTOL Aircraft Database," url: https://evtoldatabase.org [retrieved 2 December 2022].
[39] Hirschberg, M. J., "V/STOL: The First Half-Century," Vertiflite Vol. 43, No. 2, 1997, pp. 34-54.
[40] International Organization for Standardization, "ISO 3166 — Country Codes," url: https://www.iso.org/iso-3166-country-
codes.html [retrieved August 2022].