The Future of Advanced Air Mobility

FAA's Aircraft Certification Chief Says It Must Flexibly Close Regulatory Gaps for New Aircraft

As the aviation industry enters a new “golden age” ripe with innovation, regulators have been struggling to keep up with the rapid pace of technological advancements. With no new regulatory framework to govern novel technologies designed for advanced air mobility (AAM), such as eVTOL air taxis, the U.S. Federal Aviation Administration sees a need to make some changes to its certification processes. So said the agency's executive director of Aircraft Certification Service, Lirio Liu, during the opening day of the Revolution Aero conference in San Francisco on September 12. 

To accommodate the blooming AAM industry in the meantime, the agency needs to be flexible in applying existing regulations for conventional aircraft to new technologies, according to Liu. “This new golden age of aviation is truly amazing, but it clearly presents some challenges for the FAA,” she said. “Our current regulations are designed over years for the traditional airplanes and helicopters and their operations, and we're not seeing just airplanes and helicopters and the same operations.” 

Liu's keynote speech to Revolution Aero delegates covering a broad cross-section of AAM stakeholders came four months after the FAA unsettled the nascent industry with suggestions that it felt the need to make fundamental changes to the way new aircraft are certified. It was reported that the regulator intends to switch 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 small fixed-wing aircraft. Liu, an FAA veteran, was appointed to her current position in May around the time of the apparent change of approach by the agency.

The agency subsequently sought to play down the scale and pace of any changes to previously understood regulatory processes. But while eVTOL aircraft developers have not openly pushed back against the possible changes, the Vertical Flight Society complained at the time of "a lack of clarity and consistency" on the part of the FAA. Liu did not specifically address the question of the 21.17 (b) rules in her presentation.

In addition to electric aircraft and eVTOL air taxis, the FAA is now also faced with certifying new flight technologies, such as artificial intelligence for pilotless aircraft, electric and hydrogen-powered propulsion systems, supersonic and hypersonic aircraft, and sustainable aviation fuels. The advent of these new technologies has exposed some gaps in the FAA’s regulatory framework, but that hasn’t stopped the agency from providing the necessary approval to bring such innovations to market—although the certification process can be time-consuming. 

“Amid all this innovation, the FAA has a proven track record for safely certifying and integrating the new and novel designs and safety-enhancing technologies into the national airspace system,” Liu said, pointing to examples like uncrewed aircraft systems (UAS), autopilot technologies, and the automatic dependent surveillance-broadcast (ADS-B) system. 

“Despite regulatory gaps...our ongoing certification work is possible because we can leverage our current regulatory framework,” Liu said. “We have flexibilities in that framework. We don't always use them, but we're getting better and better at doing that. Those frameworks will allow us to have technical policy specialists to develop project-specific regulatory requirements tailored to the unique aspects and the new designs we're seeing. These flexibilities can come in the form of special conditions or unique airworthiness criteria which we call a special class.”

Liu explained that, when integrating new technologies and designs, the FAA is taking a risk-based incremental approach, also known as an operations-first approach, to authorize operations using existing regulations and get new aircraft flying sooner. “Once we have the aircraft in the air flying, we're able to take advantage of the lessons learned from these operations that we had approved to help us start refining that future policy,” she said. “Doing this, we've been able to better target our regulatory focus while ensuring that innovation drives the industry forward.”

One example of the FAA’s operations-first approach is how the agency enabled drone flights through its Part 107 rules that cover small UAS. “We allowed certain operations [and] made the exemptions, so we gained those lessons learned.”

“While it may at times be a challenge for a safety-focused regulator like the FAA to keep pace with the speed of the private-sector innovators, I'm happy to say that the FAA is committed to ensuring that we have a robust, agile certification system, along with a strong and capable organization to accommodate new and novel design ideas," Liu said.