Reference? I have yet to find one other than the local FSDO's word. This logic could be tied into the landing light required argument.
Some say its required for rentals, some say its not. Even different FSDO's have different opinions on this one.
A 100-hour is not required for a rental airplane. That's not because a rental isn't a hire. Of course it it. A 100 hour is not required for a rental airplane because the applicable regulation says:
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no person may operate an aircraft
carrying any person (other than a crewmember)
for hire, and no person may give
flight instruction for hire in an aircraft which that person provides, unless within the preceding 100 hours
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The 100 hour applies when there is flight instruction for hire and when there are paying passengers on board. A pure aircraft rental is neither. It has nothing to do with whether a rental is "for hire"
But the landing light regulation is a little different. It says
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If the aircraft is operated for hire, one electric landing light.
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So already, the landing light requirement is broader that the 100-hour one since it (at least) applies to cargo operations in addition to passenger-carrying ones
Rental qualifies? I'm really not sure. The FAR meaning of operate includes "authorizing use" and if you are renting aircraft, you are definitely authorizing the use of an aircraft and receiving a fee for it. Sure sounds like operating an aircraft for hire.
But I know that when we commonly think of the phrase for hire, we do think of a person - in the sense that at taxi is "for hire" and a "U-Haul" rental is not.
But, tgrayson, I've searched the Summit CD on this and have not been able to locate an FAA Legal opinion that says one way or another whether "for hire" necessarily contemplates a pilot being included outside of the context of carrying passengers or cargo.