The Future of Advanced Air Mobility

FAA Denies It Will Overhaul eVTOL Aircraft Certification Rules, But Change in Approach Annoys Industry Groups

The FAA has played down suggestions in a media report this week that it is instigating fundamental changes to the process for certifying eVTOL aircraft. A story in The Air Current published late on May 9 said that the U.S. regulator is switching to a process in which “powered-lift” eVTOL designs will be certified as a “special class” under its 21.17 (b) regulations, rather than under the 14 CFR Part 23 rules used for most existing smaller fixed-wing aircraft.

In a written response to questions from FutureFlight, the FAA implied that any changes will be more gradual and will not mean a complete abandonment of the Part 23 framework, which eVTOL aircraft developers have been led to believe would be acceptable as the basis for type certification. However, industry groups, including the Vertical Flight Society and the General Aviation Manufacturers Association, have expressed frustration over what they see as a lack of clarity on the FAA's intentions.

“Our process for certifying the aircraft themselves remains unchanged,” said the FAA statement. “All the development work done by current applicants remains valid and the changes in our regulatory approach should not delay their projects.” A spokesperson for the agency added that the 21.17b framework “allows for Part 23 certification standards.”

The FAA has established the new 21.17 (b) "special class" certification pathway, incorporating various regulations from the current Part 23, Part 27, and Part 29 structures. Part 23 rules apply mainly to smaller fixed-wing aircraft, and engagement so far between eVTOL manufacturers and the FAA seems to have been based on the assumption that these would form much of the foundation for the certification process.

However, the FAA’s short public response to The Air Current report—which described the change as "a stunning development that appears to have largely caught the industry off guard"—leaves room for remaining doubt among eVTOL aircraft manufacturers as to further possible amendments to the regulatory process. The companies, many of which are start-ups that have promised investors that revenues will start flowing in the next couple of years, are racing to meet targets for completing type certification, from 2024 in the case of the frontrunners.

The FAA response acknowledges that some regulatory changes are in the works, without clarifying what form or direction these may take. It implied that the anticipated changes, whenever these might be confirmed, could focus more on areas such as flight crew training and operational requirements.

“The FAA’s top priority is to make sure the flying public is safe,” said the statement. “This obligation includes our oversight of the emerging generation of eVTOL vehicles. The agency is pursuing a predictable framework that will better accommodate the need to train and certify the pilots who will operate these novel aircraft.”

FAA added that it sees a need for increased "flexibility" in setting and enforcing requirements for Part 135 commercial operations of eVTOL aircraft in order to, "eliminate the need for special conditions and exemptions." The agency indicated it is modifying its regulatory approach because regulations designed for traditional airplanes and helicopters, "did not anticipate the need to train pilots to operate powered-lift, which take off in helicopter mode, transition into airplane mode for flying, and then transition back to helicopter mode for landing."

The Vertical Flight Society, which is closely involved in engagement between eVTOL companies and regulators, expressed some disappointment at what it described as a "lack of clarity and consistency" on the part of the FAA. "Part 23 is the appropriate airworthiness standard for electric aircraft, whether the propellers thrust forward [eCTOL/eSTOL aircraft] or vertically [eVTOL]," commented the group's executive director, Mike Hirschberg. "This is what the industry has been expecting for more than a decade.

Hirschberg added that "21.17 (b) results in a special product that doesn't fit into operational constructs around the world. It's not internationally recognized, so using it as an airworthiness framework could significantly dampen operations of U.S. certificated aircraft in other countries. The FAA needs to work with the eVTOL community more closely if the agency wants to continue to lead in aviation in the coming decade."

This apparent frustration on the part of the industry was echoed by the General Aviation Manufacturers Association, which also has strong connections with eVTOL pioneers. The group's president and CEO Pete Bunce issued a written statement that described the FAA's change of course as, "in our minds detrimental to safety, and [that] increases the workload on the FAA dramatically. This is bad policy for so many reasons."

In March, the U.S. Department of Transportation’s Office of the Inspector General (IG) announced its intention, at the direction of Congress, to audit FAA certification processes for urban air mobility (UAM) vehicles at the request of the House of Representatives' Committee on Transportation and Infrastructure. The audit will seek to determine the FAA’s progress in establishing the basis for certification of new aircraft, such as eVTOL designs, on the grounds that these could be operated autonomously.

In a statement, the IG office noted the challenges associated with the use of existing Federal Aviation Regulations (FARs) to certify these aircraft. While the FAA has already begun reviewing applications for certification of eVTOL vehicles, regulators intended the existing standards to apply to traditional small aircraft with a pilot on board. Those regulations do not necessarily apply to UAM aircraft that might fly autonomously. Meanwhile, UAM aircraft contain technology and systems that are novel compared with what current small aircraft provide and require more scrutiny during the certification process, said the IG office.