The Future of Advanced Air Mobility

Flexibility Over Certification Boosts Confidence in Urban Air Mobility Progress

Industry leaders agree that recent changes to light aircraft certification rules, coupled with the substantial interest and investment that urban air mobility (UAM) is attracting, are increasing confidence that the emerging sector is accelerating towards entry into the market.

But during a June 30 webinar on “General Aviation Post Pandemic – An Opportunity to Provide Alternative Air Transportation,” hosted by the American Institute of Aeronautics and Astronautics (AIAA), participants debated how rapidly the sector might develop given issues surrounding certification basis, automation, and training.

“We've never seen the amount of attention, quality people, dollars of investment, and the government working with us,” said Aspen Avionics president and CEO John Uczekaj, who added, “That's why I have confidence that what's happening right now will be accelerated.”

On the certification front, EASA late last month released for consultation its second publication of proposed means of compliance with the special condition for vertical takeoff and landing (VTOL) vehicles. The U.S., however, is working through VTOL/UAM projects individually, said Mel Johnson, the FAA’s director of organizational performance division in the Aircraft Certification Service.

“Unlike EASA, we haven’t come up with something that we can send out as generalized conditions," Johnson said. "We’re working directly one on one with each applicant.” He added that as the agency evaluates specific technologies and designs, it will publish special conditions or exemptions available as necessary. “Hopefully, soon we'll be able to see some of that.”

Helping the agency in its efforts, he said, is the new performance-based approach adopted under the Part 23 rewrite. Under this approach, the FAA is focused on ensuring that a vehicle meets the safety requirements rather than providing the prescriptive manner on how to get there.

“We have been working very hard in the FAA to try to make sure that we don't have a situation where we develop standards that prohibit or create such high barriers that we stopped safety enhancements from entering into the market and that's been something that we've been quite passionate about,” Johnson said.

In his view, the industry's highly risk-averse instincts could stand in the way of progress. "That would be a tragedy," he commented. "We want to make sure that we provide a way for compliance…that allows for innovation to happen and safety enhancements to come into the system.”

That includes innovative concepts such as UAM and electric propulsion or “many of the things that we're currently seeing coming into the market.”

The FAA understands that bringing more predictability into the regulatory environment is important because otherwise, it becomes a barrier that could discourage development, investment, and confidence, Johnson said. “We’re working really hard to try to help make sure that we're not a barrier for that kind of innovation...for things that bring both safety and accessibility to aviation.”

Starr Ginn, advanced air mobility national campaign lead for NASA, noted the focus on Part 23, which is written for “normal category aircraft,” rather than Part 27, involving “normal category rotorcraft,” and said, “I feel that there's a gap in that these are vertical-lift vehicles and there's very specific, flight-test techniques, handling qualities, and crosswind capabilities that need to be assessed that don't quite fit nicely in Part 23.”

While Johnson noted that “Part 23 was amended recently to be much more inclusive of technology…and forward-leaning,” he agreed that it wasn’t intended to take the place of rotorcraft regulations. “As we work through everyone's requirements for these new aircraft that have the vertical-lift component, we have to develop certification basis that incorporates some of that kind of thinking, some of those kinds of risk mitigation that are seen in other parts,” he said. But he added, “We tried to create the airworthiness requirements with a much more open mind.”

Ginn also pointed to other issues that need to be resolved, such as those regarding battery power, noting that it takes years to develop the necessary empirical data to demonstrate acceptable levels of safety.  Technologies can evolve quickly, she said, “but we have a brand new distributed electric propulsion system that doesn't have a lot of history. We have to change Part 33 endurance testing because it speaks to pistons, not our electric motors. There's a lot of standards that need to change to enable this market, and that process doesn't go quick.”

Greg Bowles—the head of government affairs at Joby Aviation who played an integral role in the government/industry Part 23 rewrite effort—noted that his company has been talking through such issues with the FAA for its own eVTOL, and “we now have our certification basis in place with the FAA.”

Updating Joby’s activities, Bowles noted that the company has been working in the UAM space for more than 10 years and began flying subscale aircraft in 2015 and full-scale aircraft in 2017. The company has amassed more than 1,000 flights on various test articles and started the formal certification process in 2018 with a schedule to complete type certification in 2023.

“Our certification basis would have us essentially be defined as an airplane that can also take off and land vertically,” he said.

The FAA is working through individual applicants until it has enough standardization for broader policies, Bowles added. “Through the work I've done with ASTM and other standards bodies, we certainly look to standardize these new approaches more broadly.”

The standards body ASTM, which is establishing global consensus standards that regulatory authorities can accept, has addressed standards for electric propulsion, as well as other areas, such as flight controls, he said, contending that he believes the “regulatory situations are actually not a risk.”

From an operational standpoint, the webinar participants agreed that the move to full autonomy will be a slow evolution. Bowles noted that Joby plans to operate, as well as manufacture, its aircraft. Plans call for standing up its commercial operations in 2024 under Part 135 and initially flying in a conventionally piloted manner before transitioning to remotely piloted flights.

“The methodical approach that we're taking is intended to fit into today's system using today's rules, using today's pilots that will take some additional training to fly the aircraft safely,” Bowles said. “And then beyond that, there's lots of growth paths.”

The issue of higher levels of autonomy is “certainly something we’re all watching keenly. In the very near future, you're going to see a number of companies that will be able to do that….The speed at which things happen nowadays is astonishing.”

Bowles and others believe it will be a transition that occurs as more automation technologies are incorporated into other vehicles, from automobiles to drones.

Much of the technologies used in autonomous drones, whether or not they're beyond visual line of sight, will “bleed into urban mobility” and passenger-carrying operations, Uczekaj said. He noted the various sensors and artificial intelligence currently enabling operations ranging from pipeline to powerline and agricultural support.

These operations will lead to a “trust factor” that will be developed as the technologies transfer into general aviation aircraft, he said.

“Trust in autonomy is a big deal,” added John Valasek, an aerospace engineering professor at Texas A&M University who is also a site director at the FAA Center for General Aviation Research (PEGASAS). He said trust needs to be evaluated, both in the ability to build it but also to balance reliance on autonomy.

However, Valasek stressed that “the human is going to be for quite a while part of the system.” Pilots need to be informed and properly trained, he added, and while the technology is rapidly changing, the pilot training is the same. “You don't hear too many people talking about what needs to be done from the pilot aspect,” Valasek said.

Pilots will need to learn to work with “automation cognition,” he said, and cited an example: “When we go to urban mobility, now we're going to be in low-level urban environments, cluttered environments.”

Uczekaj, however, noted the transitions pilots have already had to make with autonomy. “I think the next generation of technology that will introduce itself in urban air mobility is in the artificial intelligence range that will make it easier for the Part 23 pilot…but it will require a different type of training for sure.”