The FAA this week provided valuable insight into how it intends to certify new eVTOL aircraft when it published the airworthiness criteria it is using for Joby’s JAS4-1 five-seat model. The proposed rule published in the Federal Register on November 8 marks the first time the U.S. air safety regulator has shown the specifics of the type certification requirements for the new class of electric aircraft. The agency is seeking comments on its FAA-2021-0638 proposals by Dec. 8, 2022.
The publication confirms that Joby’s aircraft is intended to be operated under both commercial Part 135 and private Part 91 rules with a single pilot on board and under visual flight rules. The California-based manufacturer applied for certification under 14 CFR 21.17 rules in November 2018 and because the process was not completed within the defined three-year period, the basis for type certification was subsequently updated in June 2022.
In a letter sent to shareholders on November 2 to report on the third quarter, Joby said that it now expects to complete the second stage of type certification by the end of 2022. However, the company also disclosed that it anticipates the start of commercial air taxi operations will slip from 2024 into 2025 as the FAA is now not expected to confirm its operational requirements for eVTOL aircraft until late 2024. Nonetheless, initial military operations for U.S. defense customers could still get underway in 2024.
The FAA submission confirms its intention to use sections from the 14 CFR rules to suit the new “special class” of powered lift aircraft. Essentially, the agency is cherry-picking requirements from Parts 23, 25, 27, 29, 31, 33, and 35 to “provide an equivalent level of safety to the existing standards.” Earlier this year, the agency indicated it is taking a different approach to certification in a move that raised some concern among eVTOL aircraft developers.
The proposals explain new definitions of airworthiness criteria to take into account the “unique capabilities and flight phases” of eVTOL aircraft. For instance, since not all the new aircraft are expected to be able to glide or autorotate in the event of a loss of propulsion, the FAA is proposing modifications to requirements for “continued safe flight and landing,” as well as a new definition for a “controlled emergency landing.”
The extensive FAA publication spells out significant details as to how it is treating eVTOL aircraft designs, such as ways of addressing new sources of lift that alternate between thrust-borne, semi-thrust-borne, and wing-borne through the various phases of vertical takeoff and landing flight. The document also summarizes criteria to be used for assessing powerplant, airframe structures, flight controls, and specific equipment such as cockpit voice and flight data recorders, as well as instructions for continued airworthiness.
In October, Joby conducted a private "field day" event to brief stakeholders on its progress in developing its eVTOL aircraft. The event, at the company's Marina, California, campus, included a tour of manufacturing facilities, opportunities to try its flight simulator, and a flight demonstration with one of its prototype vehicles.