Jean-Christophe Lambert is co-founder and CEO of Ascendance Flight Technologies, a Toulouse, France-based company developing the hybrid-electric Atea aircraft. It was founded by four members of the former Airbus E-Fan team, which built the first all-electric two-engine aircraft to fly across the English Channel in 2015.
Now, Lambert and his team are building on that experience to design a hybrid-electric eVTOL to serve urban and regional air mobility markets.
Alex Scerri: Jean-Christophe, can you give us some background about you and how you came about to found Ascendance Flight Technologies with your partners?
Jean-Christophe Lambert: I have an engineering background. After finishing my engineering studies I did a master’s degree in business, following which I started my career at Airbus. I held various positions in business development and project management. My last work with Airbus was on the E-Fan project and I was the project manager for the prototype that crossed the Channel in 2015. We were then working on the E-Fan 2.0, which was meant to be the first electric aircraft to be type certified, but production was cancelled in 2017. Then, in 2018, together with three of my colleagues from the E-Fan team, we decided that we still wanted to push and promote electric and hybrid technology, this time as entrepreneurs. We founded Ascendance Flight Technologies, with the Atea VTOL as our first project. Our vision for the aircraft is to be positioned for regional air mobility missions and not only urban air mobility.
Alex Scerri: Can you briefly describe how much batteries and motors have improved since the time of the E-Fan project?
Jean-Christophe Lambert: In my opinion, not so much. That is one of the reasons why we believe in hybrid technology. Battery energy density has increased by about 10 percent, which is not that much considering the timeframe. For electrical motors, there have been some key developments in terms of power density and that is very important for us. However, even here, the improvements are not ones that could be called disruptive. It is more of an incremental evolution, but with the wider adoption and accelerated development of EVs, we may see some breakthroughs transferring to aerospace applications.
Alex Scerri: Why do think that there are so few eVTOL projects based in France compared to other European countries, considering its rich industrial and aviation heritage?
Jean-Christophe Lambert: In fact, it was disappointing not to see as many startup initiatives in this field in France. This is another of the factors that pushed us to found Ascendance Flight Technologies. The way I can explain it is that when you have dominant industry players like Airbus, Safran, Thales . . . it is not easy to push the boundaries as a startup. This is one area where France can improve. There seems to be a cultural mindset that innovation and game-changing ideas can only come from the big, established leaders in the field but we know that this is not always the case.
Alex Scerri: What does the name of your aircraft, Atea, represent?
Jean-Christophe Lambert: Atea is the deity of the sky and space in French Polynesia. We liked this name and it also has the link to aerospace while reaffirming our French roots.
Alex Scerri: Is the Atea based on an existing airframe or is it being designed from scratch?
Jean-Christophe Lambert: It is a mix. I would say we based our design on some well-known principles. Of course, we then need to be innovative to adapt and integrate the vertical take-off and landing functionality into this type of airframe.
Alex Scerri: At what stage of development are you now and where do you expect to be by Paris 2024?
Jean-Christophe Lambert: Right now, we are in both the design and prototyping phase. We have flown the subscale model and are working on the 1:1 prototype. Internally, we have a strong capability of design and simulation to assess these experimental prototypes.
Being part of the Choose Paris Region initiative for UAM during the Paris Olympic and Paralympic Games in 2024 is an essential part of our roadmap and we will be flying there.
Alex Scerri: The renderings on your website show the Atea equipped with rim driven thrusters. What made you choose this technology and has it been used in other aerospace applications?
Jean-Christophe Lambert: That was more of an early rendering of a design concept than an actual choice of technology. I cannot give you more details, but what you will see in the final design will be different.
Alex Scerri: Will this be a short take-off and landing (STOL) aircraft or a pure VTOL?
Jean-Christophe Lambert: It is primarily a VTOL aircraft. However, our chosen configuration gives us the flexibility to revert to STOL capability in certain cases, for example to permit a safe landing after a failure.
Alex Scerri: Is the 2,000-kilogram (4,410-pound) maximum take-off weight quoted in the Vertical Flight Society website correct, and is this for STOL or VTOL operation?
Jean-Christophe Lambert: Yes, that is close to the actual figure and that applies to VTOL take-off and landing.
Alex Scerri: Also, from the rendering, is it confirmed that you will not have doors to cover the lifting fans during cruise flight and wouldn’t that impact your cruise performance? The Vertical Flight Society entry for your project states a 150 km (93 miles) range, which appears quite low for a hybrid aircraft designed for the regional air mobility mission.
Jean-Christophe Lambert: We will not disclose the configuration details yet. As for the range you are exactly right and that is what drove us to the hybrid solution which gives you better range and speed than what is currently possible on batteries only. The actual range we are projecting is 450 km (280 miles), possibly more.
Alex Scerri: Are you planning to use a ballistic parachute?
Jean-Christophe Lambert: EASA’s SC-VTOL does not require it as the aircraft has to have the capability for continued safe flight and landing after a single failure. However, we are keeping our options open and we are following how the regulations and the market requirements evolve.
Alex Scerri: Is the thermal component of your hybrid unit a gas turbine engine and have you selected the supplier?
Jean-Christophe Lambert: Yes, it will be a gas turbine engine and we have narrowed down our selection to just a few options and that is something that we will freeze very soon.
Alex Scerri: In case of a failure of the gas turbine, can you still land vertically and what would be your flight endurance in airplane mode on batteries only?
Jean-Christophe Lambert: We have a few options in this case. What I can say is that we will have the capability for continued safe flight and landing after a single failure.
Alex Scerri: Do you expect to look at other technologies in the future to replace the gas turbine?
Jean-Christophe Lambert: Absolutely and that is part of our DNA. When other options for energy sources such as hydrogen or synfuel become available, it will be easy to integrate these into our power train.
Alex Scerri: Do you plan to sell the aircraft to operators or do you have a business model to operate a fleet yourself?
Jean-Christophe Lambert: Primarily we plan to sell the aircraft to operators because there is a demand for that. However, we will be providing a very comprehensive service to our customers in all aspects of operating the aircraft.
Alex Scerri: Do you plan for your aircraft to be autonomous in the future and what do you think is the biggest challenge for this from the engineering perspective?
Jean-Christophe Lambert: Yes, it’s the long-term goal. It will be piloted first, but we are already developing some bricks that will help to achieve autonomy. In our case, we are targeting this for after 2030.
As for the challenges, I think that one part will be certification. The method we are using to certify aircraft today is very deterministic. Autonomy requires some artificial intelligence bricks that by definition are not deterministic. At present, when you design embedded software, you have to apply some strict, predetermined rules to code it, such as Design Assurance Level (DAL) A, DAL B, DAL C etc. This mindset will need to change when we come to certify AI, while still ensuring the same level of safety.
There are some other issues like designing a reliable sense-and-avoid system, but we can overcome these as we consider that the airborne threat environment is more predictable and less dense than for example the challenges faced by autonomous vehicle designers at street level.
Alex Scerri: Do you plan certification under EASA’s SC-VTOL and do you plan to do a parallel certification with the Federal Aviation Administration (FAA)?
Jean-Christophe Lambert: We are actively working with EASA on certification under SC-VTOL. We are planning certification with the FAA at a later stage but we are following closely the process that the FAA will be using to certify eVTOL aircraft so we will be ready.
Alex Scerri: Some manufacturers think that certification under EASA’s SC-VTOL is more challenging to achieve. What are your thoughts on this?
Jean-Christophe Lambert: You could say that EASA’s SC-VTOL is more demanding than other regulations, so I agree that it’s a challenge. However if want to reach a big market like being able to land in or take-off from the urban centers, you need to ensure that you do this at the appropriate safety level. The FAA approach is to have bespoke regulation for each project that maybe could be easier to certify. The advantage of EASA’s SC-VTOL is that it will be one standard text that will provide a level playing field for everybody. I am sure this will help the industry to be more structured and collaborative. Both approaches have their pros and cons. As for us, we are comfortable and moving forward with SC-VTOL.
Alex Scerri: Where do you plan to manufacture the aircraft?
Jean-Christophe Lambert: What I can tell you today is that we have a close collaboration with Région Occitanie, around Toulouse. We have some short- and medium-term plans and a shared roadmap with them and they are very supportive as they also have the vision for a cleaner and more sustainable aviation industry. However, it remains a global market, so Ascendance Flight Technologies will not only be French, not only European, but we will have a worldwide footprint.
Alex Scerri: Lastly, as one of the founders and leaders of the company, which is the one thing which sometimes keeps you awake at night?
Jean-Christophe Lambert: Thankfully I sleep well! It’s hard to say really. Being an entrepreneur in this kind of startup is a constant challenge. We are working every day and all the 12 members of the team are constantly putting in a lot of energy and effort, as we all believe in this project. We are still growing and one of the main tasks is to find the best people who are up to this challenge and not fearful of sometimes facing the uncertain and disruptive path needed to design and certify this new aircraft technology.