The Future of Advanced Air Mobility

FAA Issues G-1 Certification Basis For Lilium's eVTOL Aircraft

The FAA has issued Lilium with the G-1 certification basis documentation it needs to secure type certification for its eVTOL aircraft in the U.S.. According to the German manufacturer, the milestone announced on June 26 makes it the only eVTOL developer to have received G-1 clearance from both the FAA and its primary airworthiness authority EASA.

According to Lilium, it is on track to achieve initial type certification by EASA for the six-passenger Lilium Jet in late 2025. Under the Bilateral Aviation Safety Agreement between the European Union and the U.S., the company then expects to receive concurrent approval from the FAA.

The company is one of a few eVTOL vehicle developers seeking concurrent approval on both sides of the Atlantic, with others including the UK’s Vertical Aerospace. EASA is processing type certification applications under its Special Conditions VTOL requirements.

The FAA is taking a different approach to assessing airworthiness approvals for the new category of aircraft basing its approach on Part 21.17(b) rules rather than Part 23. U.S.-based manufacturers Joby and Archer have both received G-1 issue papers on this basis, and in February Joby reported that it has now completed the second of five stages to establish the means of compliance for its aircraft.

According to a source at Beta Technologies, it has now submitted the Stage 3 G-1 application for its Alia 250 eVTOL vehicle. The U.S. company is also seeking to certify its CX300 electric fixed-wing CTOL aircraft, which is derived from the Alia 250, and also the electric propulsion system it has developed in-house.

G-1 Process Has Multiple Steps

There are essentially four stages to the FAA's G-1 process, starting when a company files an application for the issue paper. The second stage is when the FAA initially grants this, which starts a process in which the company submits a response to what the agency is proposing ahead of the public consultation and confirmation of the basis for certification. Some companies chose to conduct a dialog with the FAA ahead of applying for the G-1 and, in the case of new eVTOL developers, they can benefit from seeing what is said in the public consultation around other companies' applications.

“We are the first powered-lift eVTOL pioneer in our industry holding a certification basis from EASA and the FAA,” said Alastair McIntosh, Lilium’s chief technology officer. “This is a major step towards our goal of achieving early certification of our aircraft in key markets to support a worldwide entry into service.”

Under the FAA process, Lilium and EASA will both provide further information to the U.S. air safety agency before it publishes the G-1 documentation for public consultation. Lilium is also working towards achieving EASA design and production organization approval.

Meanwhile, Swedish company SKF is now helping Lilium to design bearings for the 30 electric ducted fan motors installed in the wing and canard. Under a supplier agreement, Gothenburg-based SKF is producing lightweight bearings for the first type-conforming Lilium Jet.