Piper P/N 23013-000 – typical Dura flap transmission. This is the final product you will receive after service. Note – this is another owner-produced request product.

Dukes Transmission

New field coils and Kevlar pole shoe insulators. The silver/clear cadmium is current; forget the gold cadmium.

This information including the Dukes type transmission is provided because there are 2 types of transmissions; it would certainly be rare but I suppose possible to find the Dukes installed in the flap system.

The Dura transmission and the electric motor can be conditionally repaired – call for information.

Air Parts of Lockhaven and Pifer’s Airmotive claim FAA approval for performing the electric motor repair.

These flap motors from Comanche Gear are $500, exchange, owner-produced request required.

The Piper Comanche Service manuals state that these transmissions require a 500-hour inspection and service; often ignored for lack of awareness. See the manual reference here.

Also if I may deviate a bit from the SM recommendation [500-hour]; if the Dukes special grease is used, in my opinion, this can be stretched to 1,000 hours. Shame on me!!

Comanche Flap Motor & Transmission – Exchange Service

The flap motor is smaller than the gear motor; I’ve seen a few substitutions. Your core must be the Piper P/N 475–192, American Bosch P/N MO721082A. No landing gear motors allowed in this application. I have plenty of the flap motors available. A motor with new field coils, rewound and dynamically-balanced armature, MIL-Spec connect wires, and cadmium plated housing is $500, EXCHANGE.

Dukes Transmission

American Bosch flap motor P/N MO721082A

Transmission Service

Transmission service as specified in the Service Manuals. This applies likewise to the landing gear transmissions; wouldn’t that figure? I’ll wager the flap transmission service is one of the most-ignored components on the Comanche.

Brake Coil Assembly

Comanche Flap Motor

The Flap Motor Internals

Brake Coil Assembly

Brake Coil Assembly; same for landing gear application.

Brake Coil Assembly


Piper P/N 475-192 flap motor showing brush holders with MIL-Spec wires.