Lilium, the German eVTOL electric vertical takeoff and landing aircraft company, has recently moved its flight test activities to the Center ATLAS experimental flights (Air Traffic Laboratory for Advanced Unmanned Systems) in Jaén, Spain. In the town of Vilacarrillo, among extensive olive groves, the fifth generation demonstration prototype phoenix 2 progresses through an extensive testing program under the direction of the Company Chief Pilot Andrew Strachan. In an interview given to evtol.com the veteran pilot explains the type of tests that are being carried out.
Andrew Strachan joined the Royal Air Force (RAF) in 1979. Most of his flying hours have been in rotary-wing aircraft. In 1990, he completed the Empire Test Pilots’ School (ETPS) test pilot course, followed by four years of military test flights between Boscombe Down in the UK and a two-year exchange with the flight test unit US Army at Edwards Air Force Base in the Mojave Desert.
Returning to the UK in 1997, he joined Westland Helicopters, which became Augusta-Westland and then Leonardo. He was promoted to deputy chief test pilot in 2003 and chief test pilot in 2012, a position he held for seven years. He retired from that role in 2019, continuing with some consulting work for Leonardo and Boeing. His interest in eVTOLs, opened the doors of Lilium for him when the opportunity to work there arose.
Strachan explains that the choice of Spain was really quite simple. When considering the test area, the regulation makes it more difficult to do an unmanned flight than to have a pilot on board. Lilium reached the limit of the test flight envelope at the facility located at Oberpfaffenhofen Airport near Munich.
The need for a very large area meant that other locations in Germany were ruled out. A) Yes, ATLAS became the perfect place as it is located in a sparsely populated area. In addition, the Spanish authorities have invested heavily in infrastructure, which together with the good weather and available areamakes it meet all the necessary requirements for the objectives of Lilium.
ATLAS is already carrying out tests the Phoenix 2 prototypethe same one that successfully completed the tests in Germany, and will soon be joined by the phoenix 3. That is to say, the tests in Germany have been suspended for the moment, although there, in Weßling, Bavaria, it continues the development of the production aircraft.
The work routine in Spain is a traditional flight test process and it is developing at a good pace. Vehicle preparation and testing begins the day before with the aid of a technology demonstrator simulator that allows the crew (a remote pilot) and flight test engineers to design and practice the test profile.
On the same day of the test, the team meets early, around 6:30 in the morning, which is when the ideal flight conditions occur. If the time were delayed, the thermal activity and the associated turbulence could complicate the operation. For this reason, the test flights are carried out around 8:00 in the morning and end around 10:00 with the last preparations of the plane, briefings and, in parallel, other tasks such as charging the batteries.
The flight itself follows a predefined set of procedural steps. Once back, the reports are written and all the data is collected to analyze them and prepare for the next day’s test.
The Phoenix 2 is an aircraft designed as a unmanned technology demonstrator and is currently equipped with test instrumentation. The main advantage of unmanned tests is safety. In modern flight tests, the risk is reduced to a minimum. However, as can be expected especially at this early stage of development, there is always a chance, however small, that a test flight might not go as planned. With today’s technology, such as high-bandwidth data links, it is possible to collect a large amount of data without the need for a pilot on board.
One of the disadvantages of these tests is the need to a larger test area compared to a manned aircraft. The other is that although the plane is packed with sensors, a human pilot could detect other signals such as slight vibrations or even smells. In the case of Lilium, later the tests of the production aircraft will be carried out with a pilot on board. At that stage, this condition will be essential, since the human-machine interface (HMI) will also be tested.
Work schedule and tests for certification
The technology demonstrator is developed to mainly test the concept. It also provides all kinds of data and information that will be applied to the production aircraft. When certifying an aircraft, the vehicle must conform to the production design. Therefore, the current tests provide security and confidence that assumptions being done to scale the demonstrator to the larger production aircraft are valid.
The supply chain disruptions that all industries have been experiencing in recent months forced Lilium to rearrange their schedules. The demonstrators will continue to fly as long as they are needed. The production aircraft will go into production in 2023. Your tests, based on the experiences with the demonstrators, should last about 18 months.
Lilium seeks to obtain a simultaneous certification for the Lilium Jet, both with EASA (European Union Aviation Safety Agency), the European Aviation Safety Agency, as with the FAA (Federal Aviation Administration), the United States Federal Civil Aviation Administration. The main certification is EASA and the company works through it with the FAA to promote this simultaneous certification.
At the end of the interview, Strachan assures that “the future of this industry is very credible and anyone passionate about aviation should follow its evolution. Anyone who enters this business now will be part of the revolution. I encourage everyone to have faith in advanced air mobility and while a lot of work has already been done, we are at the beginning of a very interesting journey.”