skykrawler

Update on the M20K airplane with the popping "Gear Cont" circuit breaker. On the flights immediately preceding this activity the circuit breaker had popped two or three times after retract. The airplane was jacked and the belly #2 panel removed for access to the limit switches and relays. All the the wiring was thoroughly examined including the left side cabin interior where the harness for the gear switches and relays come up (a pinch point) and going forward until it goes into the harness and is untraceable. The circuit breaker area was examined for loose lugs and rouge loose screws. The wiring through the gear safety switch was checked (a path for control voltage). The gear was cycled >25 times (with the airspeed safety switch satisfied) and the CONT circuit breaker never popped. Two halogen 37 watt bulbs were connected in parallel to the up relay coil input to increase the load on the 5 amp control breaker, the actuator breaker was pulled and the gear commanded to retract. This powers the up relay and the lights continuously - the CONT did not pop indicating the problem is not a weak circuit breaker or 'continuous relay on' load problem. The up limit switch was cycled by hand many times each time turning the up relay off/on - no problems. A short to ground from the relay coil input pops the breaker verifying the breaker will operate. The up limit switch was replaced with a new switch and the gear operation (retract stop point) checked. The lower gear door on the left (port) side was too tight and adjusted. All the gear activity caused the wire to light bulb socket under the floor to fatigue break (a previous repair) - this was repaired with better strain relief. The gear was probably cycled 40 times total on the jacks and the breaker never popped. The airplane has since flown twice with 8 retract cycles with no popping of the circuit breaker. One could surmise that replacing the up limit switch fixed the problem but it is hard to understand given the circuit design. Time will tell.

When I look at the TCDS I see nothing that requires the G1000 to be in the airplane. Only a mention of the certification basis allowing it to be in there.

I think it's the same for both.

Technically an annual is an inspection. Often the oil and filter is changed - the filter must be inspected. An AD may require some maintenance. Some folks assume overall maintenance will be performed, but that is a discussion that must be had with the shop.

I spent 10 minutes trying to cross that 66-4 number and couldn't find anything.

Since the popping breaker is the 'Gear Control' the only thing pulling current on it is the up and down gear relays and maybe a light (not the actuator, which has its own breaker). Plan to test the control breaker by putting a load on it with something about 60 watts power. He called a Mooney service center and they suggested the up limit switch was causing the up relay to engage constantly. But, this would cause the gear to run against the stop and also cause the 'Gear Act' breaker to pop. It could be a diode going bad on the up relay that shorts intermittently. That would splain it, but only if it happens during retract - once on the limit switch power to the relay is removed. Another symptom I heard described is: the gear is retracted and the breaker is popping. The gear lever is moved to command gear down, the breaker is closed and remains closed, and the gear extends.

Another M20K owner at my airport is having a similar problem. "Gear Cont" breaker, intermittently popping the breaker. We're going to dig in when he gets back from Florida.

Of course the common instrument installed is a combination turn rate / turn coordinator. If all you need it a turn coordinator then get one of these....and ditch the gyro rate indicator.

Too much stock is placed in NTSB reports. Especially in the light aircraft domain. Here is an example:

Is that US or Canadian dollars?

Has a reserve - probably same as buy it now. https://www.controller.com/listings/for-sale/mooney/aircraft?gad_source=1&gclid=CjwKCAjwnv-vBhBdEiwABCYQA1lkjDJRJeLMnHy5xQG_VBYDCZQAEcr8XFW5F1demXH-3vSh5fcV1xoCCDgQAvD_BwE

The OP was in 2021.

Maybe they used brake pad rivets

Fairly obfuscated. "Operators have long recognized the benefits of using COTS PEDs (e.g., tablets and laptops) to perform a variety of functions traditionally accomplished using paper references." Nowhere does the AC define an EFB as an application running on a PED. It may possibly be inferred. 10.1.3. Not connected with or receiving data from any aircraft system. That's a silly thing to say. Almost every application available has connectedness - wifi or bluetooth - to receive ADS-B traffic, FIS, flight plan exchange.

Motorcycle experience taught me overtightened chains wear faster.