Narrowing the gap between US and European eVTOL certification regulations

eVTOL companies seeking certification in the U.S. and Europe will likely be pleased to see the publication of documents detailing progress toward harmonizing eVTOL certification between the Federal Aviation Administration (FAA) and the European Aviation Safety Agency (EASA).

“Archer is pleased that the FAA and EASA are moving toward harmonization of eVTOL certification standards… and believes that achieving full harmonization would provide tremendous benefits to both aircraft operators and the eVTOL industry,” said Billy Nolen, Archer’s director of regulatory affairs.

Beta Technologies noted that both the FAA and EASA “have worked tirelessly on harmonization to ensure the best path forward for the industry, both within their regions and as a whole.” The company sees the latest update as “a major step toward a mature, harmonized regulatory framework.”

In mid-June, four aviation associations — the Aerospace, Security and Defense Industries Association of Europe (ASD), the Aerospace Industries Association (AIA), Airlines for Europe (A4E) and the General Aviation Manufacturers Association (GAMA) — expressed support for greater U.S.-EU coordination on aviation safety and innovation priorities announced at the 2024 FAA-EASA International Aviation Safety Conference.

“Promoting regulatory efficiency on both sides of the Atlantic is especially important as new participants join the system,” the group said. “The evolving landscape around advanced air mobility presents an excellent opportunity to increase transatlantic coordination that will provide global scale without negative impacts on the safety and efficiency of civil aviation in a resource-constrained environment. We also support an open market for these products, which would strengthen the competitiveness of this segment of our aviation sectors.”

Kyle Martin, GAMA’s Vice President of European Affairs, echoes these views, explaining that his organisation has supported harmonisation from the outset.

“Seeing that progress is being made gives eVTOL companies in the U.S. and Europe, as well as those outside those jurisdictions, the confidence that they can enter both markets and not have to choose,” he said. “We don’t want to produce different versions of a product for different markets for any type of aircraft. We don’t do that with fixed-wing or helicopters, and we shouldn’t do that with eVTOL.”

He added that while the long-term goal is complete harmonisation, it will take time because the starting positions of the FAA and EASA are quite different.

Delving into progress

The FAA and EASA published three separate new draft eVTOL certification documents on June 10 that reflect ongoing harmonization efforts. The documents are subject to public consultation.

The FAA has published two documents, one is an Advisory Circular on Type Certification for Lift Vehicles. It contains changes to the final certification rule that the FAA has agreed to for the Joby Aviation S4 and Archer Aviation Midnight eVTOL aircraft.

“It also includes ‘essential’ and ‘enhanced’ performance approvals, setting two different safety thresholds depending on how the aircraft is used,” Martin said. “This is consistent with EASA’s ‘basic’ and ‘enhanced’ categories.”

Passenger eVTOLs will be required to meet “enhanced” performance standards, such as the ability to maintain level flight to a planned destination or make an alternate landing after a critical thrust change.

The FAA also published a draft safety continuum, with four levels of certification for motor-powered airplanes weighing up to 12,500 pounds (5,700 kilograms). The levels apply to airplanes that will carry up to 19 passengers, with respect to Functional Design Assurance Levels (FDAL). For example, the eVTOLs certified by Joby and Archer will carry a pilot and four passengers and therefore fall under Level 2A (FDAL 10^-8) for commercial purposes, similar to fixed-wing aircraft, Part 23.

However, at this point EASA maintains level 10^-9 safety requirements for all commercial eVTOL passenger operations, not 10^-8.

On that point, Martin noted that “this is the first time the FAA has published safety numbers for climbers. Although they are different now, they will one day be harmonized. Again, that will take time. EASA has always been generally more conservative than the FAA on safety issues, and they have different precedents. For example, single-engine commercial helicopter operations have never been permitted over European cities.”

Draft EASA document

EASA, for its part, has issued a second Special Condition Number for small VTOL-capable aircraft. The Agency stated that “this new number provides additional flexibility and a better alignment with recently approved regulations (e.g. Commission Implementing Regulation 2024/1111) and Measures of Compliance (MOC) that have already been publicly consulted on.

“The MOC related to the new high-performance requirement VTOL.2517 related to ‘electrical cable connection systems’ will soon be subject to public consultation, together with an update to the current MOC VTOL.2555 related to ‘recorders’. In addition, a further revision of the special condition is planned in the near future to implement further agreements between EASA and FAA.”

One of EASA’s specific agreements with the FAA is an increase in the maximum takeoff weight from 3,175 kg (7,000 lb) to 5,700 kg (12,500 lb) for SC-VTOL Issue 1. Also in line with the FAA, EASA now requires “prevention of single failures resulting in catastrophic consequences”. Safety features have also been added to address the ditching problem, including watertight chambers and automatic activation of buoyancy devices.

Martin sees the takeoff weight harmonization as very positive because it allows for the certification of larger airplanes with greater passenger capacity or longer range with additional battery capacity. He noted that it also aligns with the long-standing weight threshold between CS/Part-23 normal category airplanes and commuter category airplanes.

Martin stated that GAMA is generally satisfied with the harmonisation efforts undertaken by the FAA and EASA, recognising that the feedback process is an important part of that process.

“It’s a good start,” he said. “We’re going through our usual process, where we and experts from our member firms analyze three documents. There are 105 pages in total. Once we hear from our members, we’ll consolidate them and send feedback by Aug. 12.”

The FAA states that it “has been working with international regulators for several years to harmonize our approaches to advanced air mobility certification and integration, and this work is ongoing. This is a priority for both the FAA and EASA, and we have technical teams dedicated to this effort. Additionally, we have joined the National Aviation Authority Network, which consists of the United Kingdom, Canada, Australia, and New Zealand, to harmonize our certification criteria and integration plans. We also have cooperation agreements with Japan and Korea.”