While electric aircraft manufacturers insist they are close to certificating their designs, uncertainty abounds about operating limitations and how the aircraft will be integrated into complex airspace.
Experts addressed those issues during a panel at NBAA BACE on 23 October, a day after the Federal Aviation Administration finalised operating and pilot-training rules for “powered-lift” aircraft, a new category encompassing electric vertical take-off and landing (eVTOL) aircraft.
Panellist Paul McDuffee with aerospace firm Cobec Consulting says the eVTOL industry’s focus on aircraft design, testing and certification has overshadowed discussion about actual operating capabilities, leaving open questions about how the novel designs can and will be flown.
“I’ve been concerned about… how do you effectively operationalise these vehicles?” he says, citing battery limitations and uncertainty about the ability of eVTOLs to operate in instrument-flight conditions. “There has not been… a lot of head-down work on getting these vehicles in a state where they can be routinely operated in the,” national air space.
The FAA issued the 880-page powered-lift rule as a “special federal aviation regulation” (SFAR) – a unique method that gives the agency flexibility to tweak its oversight as regulators learn more about eVTOL operating limitations, says FAA associate administrator for aviation safety David Boulter.
Boulter notes that the FAA will define each eVTOL type’s operating limitations during certification. “The challenge really is [that] there’s not a single certified powered-lift aircraft in the world,” Boulter says. “We don’t even know the ultimate limitations of [the] aircraft because that happens during certification.”
He calls the SFAR, which expires in 10 years, a “starting point” that sets “a safety floor”.
“We have a path, and once we know what those limitations are, then we can relook at whether waivers are appropriate,” says Boulter.
