New business aircraft under Part 25 -- Single Pilot Exemption

[Mach Stall]

I'm very interested as to how difficult it would be to certify a newly designed business aircraft for single-pilot operation under FAR Part 25. (I should stress the question has to do with FAA certifying a new design -- not about trying to get some sort of waiver on an existing airplane).

I assume an exemption would have to be obtained at the time of certification based on current Part 25 regulations. I don't think this has ever been done for a fresh design - does anyone know for certain? I'm wondering about an aircraft just over the 19,000 lbs weight limit for the Part 23 Commuter Category.

I only know of one relevant example historically, but this was not a new model at the time of the certification exemption. Long ago, I think the FAA did grant Cessna operational exemption under Part 25 for its Citation S/II model in what came to be called the "Cessna Exemption" by many, but this was done after-the-fact of Part 25 certification and relying on past safety of Citation models in the argument from Cessna.

Also, it seems pretty relevant to my question that years later, when Cessna had to get a new certification for its CJ series, it did so under Part 23 Commuter Category, arguably suggesting Cessna didn't think it would be a piece-of-cake to get a fresh single-pilot exemption under Part 25.

I'm guessing it would come down to demonstrating pilot workload. If a new aircraft had twin-engine centerline thrust, would this strengthen the case for a Part 25 single-pilot exemption via reduced pilot workload?

[glum]

I looked into this as part of my MSc thesis. There were a few of us, and we concluded it was possible given current technology (autoflight, terrain and weather avoidance, TCAS etc).

The question which divided opinion is:

"What happens when the single pilot is incapacitated?"

We concluded that the aircraft would broadcast emergency warnings to the effect the pilot was out of action, and head for the nearest suitable airfield. This was preferred over a ground station taking control and effectively turning the aircraft into a UAV.

There were other considerations of course, such as determining that the pilot was no longer capable of flying - monitoring their health primarily. Also the consideration that the system may falsely detect an incapacitated pilot, so a means of over-riding the autonomous control.

For Cert, I suspect the only real hurdle is proving that the FMS & Autopilot would be capable of getting the aircraft safely to the ground.

[m39462]

A sensible consideration, but if the question is "what does FAR Part 25 actually require?" then a very literal argument could be made that incapacitation of a single pilot is not in scope.

The relevant text is found in Appendix D:
The following are considered by the Agency in determining the minimum flight crew under §25.1523:
(b)(10) Incapacitation of a flight crewmember whenever the applicable operating rule requires a minimum flight crew of at least two pilots. If this is the only remaining issue to be addressed, then the provided workload mitigations will have established that "at least two pilots" is never required. Since that was a condition for considering incapacitation, it need not be considered.

Now, I assume that if anyone actually tried such an argument the FAA would opt for sensibility and reject it as a consequence of sloppy drafting rather than the intent of the regulation, but I found it interesting anyway.