eVTOL and advanced air mobility

This category covers electric vertical takeoff and landing aircraft and the advanced air mobility programmes around them. The motors and inverters are under electric propulsion, the batteries under energy storage, and conventional helicopters under rotorcraft. A buyer here is almost always buying a future aircraft, so the diligence is about certification progress and the operating rules, not about the aircraft in the rendering.

The certification basis is constructed

An applicant for a type certificate shows compliance with the requirements effective on the date of application plus any special conditions the FAA prescribes, and for special classes of aircraft where airworthiness standards have not been issued, the applicable requirements are drawn from the portions of existing standards the FAA finds appropriate.¹ That is the mechanism a powered-lift programme is certificated under, and it is why two programmes can look similar and be years apart. Ask which certification basis has been issued, how many special conditions are published, how many means of compliance are agreed, and how much of the compliance data has been submitted rather than planned. Ask what stage of flight testing the aircraft is in and whether the test article is the conforming configuration. Verify the approvals a supplier claims in the FAA's published design approvals rather than in the press release.⁴

The operating rules exist, and they are specific

Powered-lift operations carry their own part, which contains the qualification of powered-lift flight simulation training devices, alternate certification, training and qualification requirements for pilots and flight instructors, powered-lift type ratings and alternate aeronautical experience requirements.² Simulators used to meet training, evaluation or flight experience requirements are qualified under the flight simulation training device rules, with the powered-lift additions handled separately.³ For an operator, that means the aircraft is only half the programme: pilots have to be trained and qualified, and the training device has to exist and be qualified. Ask the manufacturer who is building the training device, when it will be qualified, and what a type rating will cost per pilot.

The infrastructure and the economics

Ask what the aircraft needs on the ground: pad dimensions, approach and departure paths, electrical service, charger type and charge time at the state of charge you will actually land with. Ask what the payload is at your mission range with reserves, at the temperature of your busiest month. Ask what the maintenance concept is and what the battery replacement interval and cost are, because that number decides the cost per seat mile more than anything else. Ask what the noise footprint is and how it was measured.

Questions that sort suppliers

Ask for the certification basis and the count of open means of compliance. Ask what the conforming aircraft has flown and in what envelope. Ask who trains the pilots and where the qualified device will be. Ask what the first ten aircraft actually cost to operate, in the supplier's own model, with the assumptions listed.