Recently, Peter Duniho posted:

"Neil Gould" wrote in message

Note that YOU were the one that set the parameters that the
"aircraft's engines are running", therefore, the regs quoted
directly answered your original question, as the PIC is always
"operating an aircraft" if the engines are running, and therefore it
is not "just a polite custom".

The PIC is NOT "always 'operating an aircraft' if the engines are
running". The FAA specifically defines "operate" to relate to "air
navigation". There is nothing in the definition that suggests that
simply having the engine running constitutes "operating".

Remember those two airline pilots that got busted for being drunk when
they boarded the plane in Florida recently? Were they not charged with
operating an aircraft under the influence? The engines were not yet
running, as I recall. So, apparently, it takes a lot less to "operate" the
aircraft than "air navigation" in reality. Nonetheless, I'll re-read the
regs to see your point of view on this.

Neil