What are eVTOL Aircraft: Electric Vertical Take-off and Landing Aircraft

Vertical Take-Off and Landing (VTOL) Aircraft have always been seen as an ideal for military applications - they do not require a specialist runway and use less physical space and infrastructure to get into the air and land.  There is a history of various attempts to create a successful VTOL aircraft; but perhaps the most recognisable and infamous example is the Hawker Siddeley Harrier Jump Jet which first entered service with the RAF as long ago as 1969.

Of course, rotorcraft such as helicopters and many modern drones are also part of the wide range of VTOL aircraft.

In recent years, there has been a wide range of interest from aircraft manufacturers, automobile manufacturers and small start up companies in creating electric VTOL aircraft (eVTOLs) which can be used to provide a range of personal transport solutions, from air-taxis and flying cars, to emergency response vehicles.  The benefits of these eVTOL aircraft is that they are quiet, can operate with a minimum of infrastructure, and will help avoid the highly congested roadways by adding a third dimension to the daily commute.

As a result there were over 200 eVTOL projects in development in June 2019, and as of February 2021, there is growing interest, with United Airlines placing over $1 billion worth of orders for eVTOL aircraft.  Some of these projects are aiming to use autonomous technology to assist the pilot (or even remote piloting).

Whilst any autonomous vehicle will have to undergo legal regulation before it can be released to the public; the complexities in creating and regulating autonomous vehicles are numerous and it is already proving difficult to obtain proper regulation for  autonomous cars, let alone autonomous aircraft where there are fewer cues that the aircraft can use.  Further, eVTOL’s will have to develop flight plans and communicate with other aircraft, as well as take account of not only pedestrians and animals on the ground (when taking off or landing), but also complications such as overhead cables; birds; cranes and other man made structures which may appear above or below the aircraft.

Advanced VTOL Crash Prevention Limited have already identified that there is an issue over safety regulation for eVTOLs and we are already taking a key part in the formation of the EASA safety standards for Emergency Descent Arrest Systems.  To fit alongside this, we have developed our own innovative Zero-Zero Safety Systen for eVTOL aircraft to help ensure that crashes are survivable.

Interest Grows in our Land Vehicle Protection System

Following the interview by Forces TV we have continued to receive a growing amount of interest in our Land Vehicle Protection System; including an article in Defence Procurement International and approaches from both the Pentagon and UK MOD who are considering a joint funding exercise to further develop the technology.

With the ability to retrofit our solution and proven ability to allow a lightweight snatch land-rover to survive a mine blast test; our innovative approach has proved both popular and a discussion point amongst armed forces personnel.


Our range of protective measures include:

  • VGAM™ - Vehicle Global Acceleration Mitigation – patented Linear Rocket Motors (LRM™) counteract mine blast lifting forces to prevent the vehicle being blown into the air.  These rockets fire within a few milliseconds of a mine blast, counteracting the lifting forces generated by a mine or IED and pushing the vehicle down to keep it grounded.
  • VAFS™ - Vehicle Active Floor System – actuators pull the floor away from occupant’s feet to prevent Floor Shock injuries by ensuring that they are not in contact with the floor.
  • CRBP - Composite Reinforced Belly Plate – a special bellly plate comprised of both steel and composite materials to minimise deformation and reduce impulse transferred to the vehicle, without needing a deep V shaped hull.  This builds on our CEO (Roger Sloman)'s materials expertise - he was the person who introduced the concept of carbon-fibre chassis to Formula One racing cars in the 1970s.

We are excited to see that finally our aim of providing Technology that Saves Lives is now being recognised on a global scale.

eVTOL Safety Standards - a Pressing Need

As the eVTOL aircraft industry moves forwards towards offering commercial air-taxi services and first responder services, there is a growing need to define how these aircraft will be safe for use within an urban environment.

Visual representation of the Air-One® site with a Hyundai Motor Group eVTOL in the centre of Coventry. Image Copyright © Urban Air Port Ltd

We are already seeing announcements of planned mini airports for electric aircraft - with Lilium currently planning to launch 10 "Vertiports" in Florida (USA) and the first UK airport for electric aircraft now announced for Coventry, but on top of this there are various companies such as General Motors, Hyundai, Airbus and Aston-Martin currently looking at personal air taxis which could take-off and land from a roof top, or even your own driveway.

Taking accident data for helicopters as a starting point, the two highest causes of accidents are Loss of Control-Inflight and System (Powerplant) malfunction, with Low Altitude Operations and Collision cited as two additional causes for accidents.

eVTOL aircraft are designed to be flown at low altitude and the lack of any (or minimal) forward momentum during the vertical take-off and landing phases means that there will be no normal lift under any wings; and no rotational effect which is used by helicopters to control emergency descents.

The strain on pilots and motors may also be much higher than for normal aircraft, due to the use of the aircraft for short-hop journeys, with many take-offs and landings per day.  Bird-strike (where the aircraft collides with a bird) is also much more common at low altitude due to the greater nuimbers of birds in flight at lower levels.

At present there is no specific certification and safety requirements for eVTOL aircraft.  As with any aircraft, before they can be used in public service, they will need an airworthiness certificate to show how they meet the relevent safety standards.

The European Union Aviation Safety Agency (EASA) has been working on the certification of such aircraft since 2018 and Active VTOL Crash Prevention Limited is part of the team formulating the EUROCAE/EASA safety standards for eVTOL aircraft with specific responsibility for drafting new standards for both eVTOL Active Safety Systems and for Stroking Crashworthy seats.

As part of this, it has become apparent that current Emergency Descent Arrest Systems designed for fixed wing and rotary aircraft will not work when it comes to eVTOL aircraft and a new approach is required.

In particular, in the NASA Langley Research Center's paper on "Challenges in Vehicle Safety and Occupant Protection for Autonomoud electric Vertical Take-Off and Landing (eVTOL) Vehicles" by Justin Littell; the author concluded that a Ballistic Recovery System should be a required piece of equipment but notes that existing systems do not advertise operation below 400 feet.

This is where the AVCP Zero-Zero Safety System comes to the rescue.

New Seedrs Fund-Raising Round

The fund-raising round on Seedrs has now been cancelled.  During the round, it became clear that many would prefer an equity fund-raising, particularly as they would still be eligible for EIS relief on monies invested.

Why not the Future Fund?

The round was a convertible loan note, fund matched by the UK Future Fund.  Unfortunately, it became apparent after launching the round that anyone who invested via a Future Fund round would not be able to claim EIS on any further investment rounds (even if they were equity rounds).

As a result, we regret that we decided to cancel this fund raising and ensure that our shareholders can continue to benefit from EIS relief.

We still require funding to maximise the new opportunities, especially for products that can provide short/mid-term revenue without any significant investment by ABBS, except in marketing costs.

1) We have a number of new contacts globally interested in using or marketing our technology which all require support.

2) The stroking seat supply has enabled the simplification of the eVTOL Safety System which also makes it much cheaper, and easier to install on the aircraft, bringing forward the need for marketing activity in the USA.

3) The belly plate programme for the Toyota Hilux is leading towards early sales which need increased marketing and technical support globally.

We therefore intend to run an equity fund raising round in the coming months; so watch out for news of this round.

You can also pre-register your interest on CrowdCube so that you will hear as soon as the new round is launched.

Interview by Forces TV

In 2020, Roger Sloman, the CEO of Advanced Blast & Ballistic Systems Limited was interviewed by Forces TV about the ABBS approach to vehicle protection.

The video appeared on YouTube and had over 35,000 views in just 24 hours, with the vast majority of comments being from people who appreciate the need for such a solution; particularly those who have been involved (or are involved) in the armed services.

This certainly helps to motivate us as we strive to bring this product to the field and continue to develop Technology that Saves Lives.

ABBS & AVCP Role in VTOL Safety Standards

Draft EUROCAE Considerations for Energy Absorbing Seats in VROL Aircraft Applications
Draft EUROCAE Considerations for Energy Absorbing Seats in VROL Aircraft Applications

Advanced Blast & Ballistic Systems Limited is presently tasked by Working Group 112 (Vertical Take Off and Landing, VTOL), Working Group 3 (Safety) of EUROCAE (European Organisation for Civil Aviation Equipment) to create requirements, guidance and specification documents covering:


  • Emergency Descent Arrest (EDAS) Systems and
  • Energy Absorbing Seat systems

for VTOL aircraft.


For Energy Absorbing Seat systems, we are presenting the case for crash-worthy seating systems in VTOL rotorcraft, and working with Seat manufacturers to gather relevant information and capabilities in a Considerations document.

This work will then move on to creating a Guidance document, where we will seek to particularly develop the requirements and concepts presented by existing EASA (European Union Aviation Safety Agency) standards (such as CS.27, CS.23 and SC-VTOL).


For Emergency Descent Arrest (EDAS) Systems, we are compiling VTOL industry views on these active recovery systems, in particular how they should (and should not) operate in flight, and developing the requirements and concepts presented by existing EASA standards, in a Guidance document.

In particular, this EDAS Guidance Document will build upon an EASA draft means-of-compliance (MOC) document, expected in January 2021, which will set-out the EASA compliance approach for parachute-based recovery systems.

These Considerations and Guidance documents for Seats and EDAS systems should raise VTOL industry awareness in these safety system technologies, as well as supporting and shaping the certification standards being formulated by EASA (and the UK CAA, Civil Aviation Authority) for civilian VTOL rotorcraft.

New Seedrs fundraising round to take advantage of new international opportunities

Since the successful Crowdcube round earlier this year there have been a number of significant technical, product, and marketing developments. These now mean that more funding than originally anticipated is required to maximise the new opportunities created. The proposed investment especially relates to products and international opportunities that can generate short/mid-term revenue but require additional marketing investment to bring to fruition. We also wish to take advantage of the Government’s Future Fund scheme, which matches investor funding 1:1, before the scheme comes to an end at 31st January 2021.

These new opportunities are all related to our basic mission to save lives and prevent serious injuries in situations where to date fatalities have been considered inevitable.

Therefore, we are planning a new funding round to launch early in January on Seedrs who have already successfully completed many rounds which take advantage of the Future Fund opportunity. This can only be done by a Convertible Loan Offer which is expected to convert within 3 years at a 20% discount to whatever price is set for the next fund-raising round. It is proposed to set a £15million cap on the valuation at the time of conversion, to be confirmed after further discussion with Seedrs.

The specific developments that have driven this new funding round are:

  1.  Wider Global Marketing of the Armoured Vehicle Technology.
    The Crowdcube round publicity generated a substantial number of new contacts globally interested in either using or marketing our technology in the armoured vehicle sector. This has enabled us to establish good coverage of immediate potential in Africa, the Middle East, and the Asia Pacific regions where current conflicts mean that mine and IED threats regularly cause casualties.Hence the belly plate programme for the Toyota Hilux which is expected to lead to first sales next year is already demanding increased marketing and technical support in these regions. There are current active opportunities in both India and Pakistan, and marketing to a number of interested operations in African is only awaiting the results of our final Hilux proof-of-concept test which is now expected to be in late March or April 2021.

    The Hilux belly-plate design has become more sophisticated than originally envisaged in order to optimise both the performance and weight. Titanium and graphene materials are potentially being incorporated as well as the existing carbon fibre element in order to maximise the strength at minimum weight. Much FEA (Finite Element Analysis) of the structure is being undertaken to optimise the design, prior to multiple jig testing planned for January/February to prove the design, followed by the full Hilux test a month or two later.

    There is no problem with making the belly plate survive the 6kg blast (simply by making it thicker/heavier) but the key is to minimise the weight and thickness of the belly plate while also minimising deformation, in order to protect the occupants whilst not degrading the performance of the vehicle too much. This is a complex design to optimise, especially as the FEA cannot be completely relied upon to give 100% correct results under the extreme blast conditions. Therefore, multiple series of tests are required to demonstrate the suitability of the different options. These include both static and drop testing of various reinforcing beam constructions to identify their relative effectiveness, followed by finally proving the optimal solution by the more expensive full scale blast tests.

    Whilst the focus for the Crowdcube funding was on continuing the development and marketing of our unique solutions for mine and IED threats to vehicles, further opportunities for bringing other ABBS group products to market have also now arisen.

  2.  Increased eVTOL Market Products and Activity.
    The development of the Active VTOL Crash Prevention Limited (AVCP) Active Zero-Zero Safety System which was originally designed to use a combination of a large parachute and retrorockets has been on the back burner for the last 18 months because of the lack of funding to pursue it. However, a new development has simplified the system concept and new products becoming available has brought forward the need to re-start marketing of the concept, and the new products, as follows:Stroking Crashworthy Seat Supply and Simplification of the Zero-Zero System.
    AVCP has obtained a supply of stroking crashworthy aircraft seats which provide protection from spinal injuries in a crash. The availability of stroking seats has enabled the simplification of the eVTOL Safety System by removing the large parachute and replacing it with a small drogue which can be deployed at any aircraft speed.

    The large parachute was originally designed to reduce the descent rate of the aircraft in an emergency to 15m/s, which the retrorockets then reduced to about 1m/s or less on landing. But the large parachute creates two problems:

    a) It cannot be opened at normal aircraft speeds or it would pull the aircraft apart. The solution for this problem is to constrain the opening of the parachute so that it opens slowly, but the corollary is that the aircraft falls a minimum of about 300ft before its descent rate is reduced to a ‘safe’ 10m/s which a stroking seat and airframe compliance can deal with and prevent spinal injuries.

    b) The minimum effective height of 300ft with a conventional Ballistic Recovery System means that there is a 300ft ‘Safety Gap’, so that the system is no use for the eVTOL market where landings and take-offs will routinely expose the aircraft to any power or control problem in this phase of flight. The large parachute essentially causes the 300ft Safety Gap, as well as complicating the rocket launch system and certification.

    Our system covered this 300ft Safety Gap by adding retrorockets to land the aircraft at a safe 1m/s, but the aviation regulators are insisting that these aircraft must be crashworthy by themselves, and hence must be designed to take a 10m/s landing without serious injury to the occupants, and stroking seats are a normal part of the design to achieve this.


    Hence, we can now change our concept by:

    a) Reducing the size of the parachute to a small drogue which can be opened fully at any aircraft speed, and which controls the aircraft descent rate to 25m/s and also maintains a level aircraft attitude during the descent.

    b) Using the retrorockets to reduce the aircraft descent rate from a maximum of 25m/s to 10m/s on landing, which is then dealt with mainly by the stroking crashworthy seats.

    The result of these changes is that the whole system becomes lighter, cheaper, and simpler to design and install on aircraft and certify for service

    This development on its own is enough to justify a renewed marketing activity for the concept, but the addition of the stroking seats to the product portfolio can potentially provide earlier sales than the main system itself, and there is also another product that may generate short term revenue whilst requiring no significant investment in R&D.

    Fire Resistant Prepreg System for Battery Box Fire Containment and Cabin Components.

    ABBS is discussing a new agreement to distribute (possibly under its own branding) a novel prepreg composite system which has exceptional fire resistance. This has already been certified for use as a battery fire containment system for eVTOL aircraft and is being evaluated for similar use in road vehicles. It can also be used for aircraft/rail/road transport cabin interior and firewall applications and has excellent Health and Safety and ‘green’ credentials, unlike the phenolic resin system generally used for these applications to date, which has serious toxicity and skin irritation problems and is currently being phased out of use where possible. The ‘green’ aspect of the system is that the resin is made from a waste product from processing sugar or other organic materials.

    The UK-based manufacturer of this prepreg is owned by ex-Advanced Composite Group personnel with whom Roger Sloman has a strong relationship so the arrangement is expected to evolve into a joint global marketing exercise to maximise the exploitation of the potential that exists, based initially on the strong position that AVCP has in the worldwide eVTOL market.

  3. EASA/CAA and FAA Philosophy on Aircraft Safety
    It may come as a surprise to the un-initiated that the regulations on crashworthiness of aircraft only deal with ‘survivable’ crashes, and no attention is given to ‘un-survivable’ accidents, which for helicopters is anything over a descent rate of 9.1m/s (30ft/s). This 9.1m/s descent rate is chosen arbitrarily as being the design criterion that the aircraft must meet and keep the G levels experienced by the occupants to safe levels. Any descent rate higher than this is deemed ‘un-survivable’ although there are many examples of higher descent rate helicopter accidents where occupants have survived with only relatively minor injuries due to the use of stroking crashworthy seats. Hence you might imagine that the regulatory bodies would mandate the use of stroking seats, and we have proposed this to EASA, but as a matter of principle they prefer to leave the aircraft designers to adopt whatever solutions they want to meet the overall G-level targets.So, by limiting the crashworthiness design criterion to a 9.1m/s Ground Impact Velocity (GIV) the authorities currently ignore the potential to provide protection above this 9.1m/s rate, which we strongly reject as a limit, and we are pushing EASA to re-consider this position.

    The whole point of our Zero-Zero system is that it is the only physically possible concept that is capable of providing full protection from any descent rate up to 25m/s, which we plan is the maximum that any aircraft will attain under the small drogue parachute in our system. Hence as far as eVTOL’s are concerned we believe that adopting our Zero-Zero system means that essentially there should be NO LOSS OF CONTROL OR POWER LOSS eVTOL ACCIDENTS THAT ARE NOT SURVIVABLE.

    In due course we will propose to EASA a new standard based on our system which will provide full protection in a 25m/s descent rate scenario. Since safety is universally agreed to be critical if the eVTOL market is going to attain its full potential, we believe that in due course the validity of the AVCP approach will eventually be recognised, but it may take a few serious accidents that kill or injure people for the industry and the certification authorities to accept it. In practice it may actually be the insurers and relevant city authorities who bear some financial responsibility for the risks that drive the market to this conclusion.

    At a recent Conference in the USA the Federal Aviation Administration (FAA), stated the issues for the eVTOL industry:-

The Elephant in the Room

These eVTOL aircraft are not airplanes nor are they helicopters:-

  • [Regulation] Part 23 (conventional winged) aircraft assume some wing lift to emergency landing.

  • [Regulation] Part 27 (helicopters) autorotate to emergency landing.

  • eVTOLs we are seeing are typically optimized for transition flight, if having wing-borne lift, higher stall-speed wings and limited flight controls.

  • Have little reason to believe right now that eVTOLs will have emergency landings with velocities and orientations that approximate 23/27.

  • eVTOLs need to consider “another way down” to controlled emergency landing within bounds of system failures.

AVCP is currently the only company proposing ‘another way down’ that realistically deals with essentially all the emergency loss-of control
scenarios that eVTOL’s will experience that
result in an excessive GIV.

The EASA (European Aviation Safety Agency) is soon to release its first guidance on the use of parachute recovery systems for aircraft.  This will tie in with the forthcoming EUROCAE guidance for Installation of Emergency Descent Arrest Systems on eVTOL Aircraft, which AVCP is responsible for drafting.

As such, now is the key time for ABBS to promote its safety solutions for eVTOL aircraft to the industry and get buy-in from the designers and manufacturers of the aircraft, showing how we can help ensure that practically almost all crashes are survivable.

Both the updated eVTOL Safety System and the new prepreg composite system offer excellent opportunities to establish these products in those parts of the global marketplace currently unaware of them, based on our existing eVTOL market contacts and presence.  We therefore need to ramp up the global marketing of our eVTOL Safety Systems to take advantage of these major opportunities.

Bringing Products to Market
  1. The prepreg composite system has already been certified for use as a battery fire containment system for eVTOL aircraft and is ready to be marketed to eVTOL aircraft designers both as an improved means of protecting the aircraft from battery fires, and for interior panels and components.
  2. Given satisfactory results from the forthcoming Hilux blast testing it is expected that current interest in the solution will result in specific enquiries and sales starting in 2021. Some further development may be required to produce a complete kit for the vehicle which is likely initially to include stroking blast seats, while an active floor system could be a later addition. Also, if required by the customers a form of active impulse counteraction to reduce the jump height/global acceleration level could be developed based on current ABBS knowledge.
  3. The stroking crashworthy aircraft seats will require specific design by our seat supplier to take account of the characteristics demanded by the eVTOL aircraft manufacturers.  These will therefore take a while to bring to market, dependent on the design considerations and regulatory pressure. Again, AVCP is responsible within the EASA/EUROCAE committee framework for drafting a new certification standard for stroking seats for eVTOL’s.

Appointment of KBS Corporate to Pursue Deals with Major Industry Players

Finally, the ABBS Board has decided that the operation has reached the stage where it is deemed appropriate to explore the potential for deals with major aerospace or defence Groups.

  • Specifically, the AVCP Ltd. eVTOL Safety System may be good candidate for a JV or a partial buyout/buy-in by a large aerospace company which has a stroking seat manufacturing operation, and this will be the early focus of the activity with a handful of the obvious potentially interested parties.
  • Equally, given the successful testing of a 6kg-capable belly plate system for the Toyota Hilux there is expected to be a surge of interest later next year from major defence-related operations, and we need to be prepared with options identified and evaluated if this happens.

Hence, we have decided to engage KBS Corporate to prepare fully professional approaches to identified major industry players and assist ABBS in considering any resulting options. Our emphasis will be on generating potential buy-in scenarios, initially for the full Zero-Zero eVTOL safety system, and then later for the armoured vehicle technologies rather than any full buy-out scenarios which would compromise any recent investments under the EIS scheme. Maximising the longer-term returns for our shareholders is always our primary objective.