As the European Union Aviation Safety Agency (EASA) develops regulations for manufacturing and operating eVTOL aircraft, it aims to strike a balance between adapting existing regimes and ensuring the flexibility demanded by a new category of platforms, senior officials told eVTOL.com.
EASA is approaching the eVTOL domain through a series of key building blocks. It first published a “Special Condition for Small-Category VTOL Aircraft” in July 2019, followed by a proposed special condition for electric and hybrid propulsion systems in January which was open for public consultation until the end of August. In May, EASA published a first set of “means of compliance” for the Small-Category VTOL Aircraft Special Condition, setting down the ways in which eVTOL manufacturers could meet the agency’s requirements in everything from flight load conditions to structural strength to cargo and baggage compartments.
The agency has had a range of public consultations around the specifications and is currently preparing a summary of the comments received that relate to May’s means of compliance, said Volker Arnsmeier, section manager for eVTOL and new concepts at EASA. However, in such a new and rapidly evolving sector, there may be the need to further adapt the certification framework in the coming years, he noted.
David Solar, head of the VTOL department at the agency, said that EASA engages in discussions with manufacturers when they apply for certification, meaning that individual approaches to compliance can be very specific. Such discussions — and early tests and trials of the platforms — could impact the broader framework looking forward.
While EASA is developing a new certification framework for the platforms, it aims to adapt existing regulations where possible, Arnsmeier said. The Special Condition – VTOL, for instance, is largely based on CS-23, the agency’s certification specification for Normal, Utility, Aerobatic and Commuter Aeroplanes, with some additional elements stemming from CS-27 Small Rotorcraft in the helicopter domain. The same is true of means of compliance, Arnsmeier added, with the agency cross-referencing the existing material where possible.
However, there are a range of novel considerations that have to be made for the eVTOL sector, Arnsmeier said, such as the number and combination of propulsion systems. Solar said that because eVTOL is not a fixed-wing or rotorcraft category, operating rather as a special class of aircraft, EASA has sought to give itself much greater flexibility in designing the certification framework.
“This kind of vehicle may not be operated like a traditional fixed-wing aircraft or helicopter,” Solar said, a uniqueness that is being seen through the business models developed by applicants. “That’s something we need to take into account.”
In particular, Solar underlined the level of automation that manufacturers are aiming to achieve at some point. “The current regulations are not fit for that and it would be very cumbersome to adapt them, instead of starting with a blank sheet of paper.”
While full autonomy “will not take place tomorrow,” Solar said it is clear that this is the likely future for the platforms on several levels, not least economical: an extra passenger means “your breakeven point is much sooner than with a pilot.”
Arnsmeier said the agency will seek to learn from its experiences with regulating drones where possible, as much of the technology behind eVTOLs is originally derived from drones and the platforms are likely to share the same airspace at some point. He stressed that eVTOLs — particularly those that carry passengers — will potentially have to demonstrate higher degrees of reliability.
The agency is also looking to the future of the infrastructure and vertiports that will be required, in both eVTOLs and drones, said Ken Engelstad, project manager for drones at EASA. Since the agency published its U-space Opinion in March, the legislative process is now being driven by the European Commission, which Engelstad said is currently drafting regulation on the subject.
The U-space draft regulation is currently technology agnostic, Engelstad said, but there will be greater focus at the next stage of regulatory development: the development of means of compliance to support the upcoming U-space regulation.
Next up for the agency is a second round of means of compliance, which will be presented at the European Rotors event in Cologne, Germany on Nov. 10-12.
“That should give better visibility on some other aspects that are developing today, and the other milestones to be completed,” Arnsmeier said.