“If it isn’t broken, don’t fix it”?

True, if you’re talking about the water pump on your car; but we’re not in this case. As pilots, airframe and powerplant mechanics we have a different perspective and responsibility; being pro-active.

Here is my short dissertation to encourage examination of the landing gear wiring harnesses on your Comanche. If you haven’t already addressed this issue, now is a good time to check the condition of the wiring and switches.

Function; the landing gear wiring harnesses and switches control 2 circuits, the gear motor through the landing gear solenoid, and the gear down indicator light – “the green light“. The micro switches are DPDT [double-pole; double-throw] configuration.

Examination; if the wires look shabby, get them out of there and replace with FAA-friendly MS22759 wire per AC43.13. Also don’t ignore the micro switches; they’ve served the airplane well; don’t ask them to do another 50 years duty without failure – replace them too.

Prolonging this issue can expose you or someone flying an airplane that you service, to a problem that they may not be properly schooled in the proper procedure to follow if the gear won’t come down, or experience a green light failure.

If a problem arises during flight, it likely will add stress to the pilot’s work load. The competency of the pilot to handle and remedy the problem will dictate the outcome. If done incorrectly the outcome can bring grief to the airplane.

Comanche Examination of the Landing Gear Wiring Harnesses
Cracked Outer Insulation