About this episode
This story begins with a squawk from the owner. It went something like this:
“When I fly my airplane, on the first landing gear retraction, the gear begins to move and then the “gear pump” circuit breaker pops. After I reset the circuit breaker, the gear retracts and extends normally with no further problems the rest of the trip.”
Weird…
What could be wrong?
It was my job to figure out what was going on.
I put the airplane on jacks and selected “gear up.”
Sure enough, the gear began to move and after a short time, it stopped mid-travel and the “gear pump” circuit breaker popped.
For once, the problem happened just like the airplane owner had reported.
I checked each gear leg for any binding, and everything appeared nice and free to move.
After evaluating and thinking through the situation, I decided it was a reasonable possibility there was an internal problem in the electric motor on the landing gear power pack.
I removed the motor and quickly discovered it was full of debris. Take a look at the brush housing:
Amazingly, a can of contact cleaner and some compressed air produced a quick transformation… and the brushes actually had lots of good material remaining:
The commutator segments were in similar rough shape when I first disassembled the motor:
