With regular frequency, questions come into the PIC with the inquirer looking for a reg citation. We are only happy to oblige. But, what if there is no reg to cite? This one falls into that category, as well as ‘Hmmm. Never really thought about that.’
Let me set the stage for you - Pre-solo student pilot with no medical and no student pilot certificate yet, but has 10 hours of flight training to date. While conducting the preflight, the student notices the fuel is rather low and taxis the Cessna over to the fuel pump to gas up. Is this ok? Can a person with no pilot credentials operate an aircraft?
Good question, right?
But, before you answer “no", consider the A&P mechanic. Since the days of Charles Edward Taylor, mechanics have been taxiing and operating airplanes with absolutely no pilot credentials; only some ground ops training, which this student also has received.
Flight time is pilot time that begins when an aircraft moves under its own power for the purpose of flight, and requires a legal flight crewmember. When taxiing to a fuel pump or to perform a pre or post annual inspection run-up check, there is no intention of flight. And in these cases, that is the key. No intention of flight means no flight time and no required pilot flight crewmember. And interestingly, it is not regulated nor otherwise prohibited.
The issue here is whether what you describe constitutes “operating” the aircraft. Here's the definition from 14 CFR 1.1:
Operate, with respect to aircraft, means use, cause to use or authorize to use aircraft, for the purpose (except as provided in § 91.13 of this chapter) of air navigation including the piloting of aircraft, with or without the right of legal control (as owner, lessee, or otherwise).
I don't see taxiing to the pump or even taxiing out to the run-up area for a maintenance run as being “air navigation”. Next, 14 CFR 61.3 refers to:
"61.3 Requirement for certificates, ratings, and authorizations.
(a) Required pilot certificate for operating a civil aircraft of the United States
Also, 14 CFR 91.13 differentiates between “Aircraft operations for the purpose of air navigation” and “Aircraft operations other than for the purpose of air navigation”. So I don't see any need for a pilot certificate to taxi around with no intent for flight.
I had a cousin that was a mechanic for United Airlines at O-Hare in Chicago. He was so thrilled when he got qualified to taxi 747s around the maintenance facility there. I don't know what kind of training, testing, or paperwork were required.
Thinking further, while it may be FAA-legal, your insurer might not approve. The open pilot waiver usually includes language allowing a licensed mechanic to twxi and run the aircraft as part of maintenance activity, but they might not feel the same way about a pre-solo student taxiing to the pumps alone. An accident in that situation might result in denied coverage even if the FAA takes no action. So I wouldn't allow anyone who doesn't meet my policy's open pilot waiver to do that in my plane.