>>>Why would this have been - any thoughts?
Brake cooling is certainly one possibility.
If the aircraft was an arrival, another possibility (more remote) is that it was a gear-down ferry flight, and that the gear had been extended the entire flight. These flights sometimes become necessary when certain landing gear-related malfunctions occur, and the aircraft can't be repaired at whatever airport it is located. The flight will be operated under a maintenance ferry permit (no passengers allowed) so as to get the aircraft back to someplace where it can be fixed. A gear-down ferry involves inserting steel pins in the landing gear mechanism that will prevent retraction, and planning the flight lower and slower. Once back at PHX
(a big maintenance base for HP
) it could then be fixed.
That could be what you saw, or maybe not....
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