PT20J

Two different circuits: The throttle switch is to warn you if the gear is not down when you reduce power to land. The squat switch is to prevent raising the gear on the ground. Because it’s difficult to adjust to compensate for aging shock disks and temperature variations both of which affect shock disk resilience, Mooney came up with an airspeed switch. I believe some airplanes were retrofitted in the field.

The picture of the plugs in the docket is not very useful because it does not show well the firing end and most of the plugs are turned so it is difficult to see the profile of the electrodes. However, from the little I can tell, they don't look that bad. Perhaps Dugosh used the go/no gauge and they slightly passed through the hole. Or maybe it was just the mechanic's observation that they were worn. Either way, I agree with @Shadrach that this didn't have anything to do with it. It just gave the IIC something to note in the report.

I would take the NTSB reports on GA accidents with a grain of salt. When I attended the Lycoming factory class there were a bunch of NTSB investigators there. They had the most interesting stories, like the toxicology report that came back from a deceased pilot that looked like an inventory for a pharmacy. But, the most interesting part was how overloaded they are. They all complained about the backlog of investigations and admitted that they often don't have enough time to get to the root cause. So, engine quit and it looks like it was disabled by detonation. Plugs look worn, timing was off, pilot operating LOP-- maybe those things caused it, maybe not. No time to try to figure it out. No one's going to cough up any more information anyway. Just note it and move on to the next report.

It should be pretty tight. Spec is 5/16" deflection for 10 lb. applied force. I usually check it with a torque wrench at annual and just go by feel in between. SI 1129D Alternator Belt Tension, Methods of Checking.pdf EDIT: FWIW, I haven't needed to adjust mine since we installed the new one with the rebuilt engine 500 hours ago.

If it really has anything like 0.1" of play there is something more seriously wrong than lack of lubrication. The whole bearing is only 0.63" in diameter. If it were mine, I'd take it apart and figure out what's up. Elevators are pretty critical and looseness might affect flutter margin. According to the manufacturer, it's a single row ball bearing. I contacted RBC about it several years ago because there were some posts here suggesting that it shouldn't be lubricated because it was sealed and spraying oil into it would wash out the grease. But, according to RBC it is not sealed and should be lubricated periodically with a light machine oil. I use LPS-2. https://productinfo.rbcbearings.com/item/single-row-ball-bearings-standard-series/rbc-airframe-bearing-specials/pn4a-2

In engineering we have a saying that there is no such thing as a single change.

The replacement gear is thicker by .060"

FWIW, everybody seems to refer to the nose gear as a "truss". Actually, the nose gear comprises three parts: the upper part is the truss, the middle part is the leg, and the lower part is the spindle. It is usually the leg that gets the dents, However, if the damage is severe enough it can damage both the leg and the truss. Check the damaged parts against the IPC to determine which parts need to be replaced or repaired. If the damage is over 1/32", I would not purchase the airplane until after it was repaired. If you buy it and move it and it collapses you will be the proud owner of an expensive repair.

Unless I'm asked to keep the speed up, I generally power back to 20" clean when being vectored, and then back to 15" when intercepting the final approach course. This gets me slowed down to 90 KIAS by the time I'm one dot from GS intercept. I set my gear horn for 12".

FWIW, I have my mags done at Aircraft Magneto Service. They've been in business for a long time and have a good reputation.

If D&B is a repair station it will have a work order detailing what was done. You could ask for a copy. I would want to know if they replaced the condensers. Metal transfer across the points can caused by a bad cap as I recall.

The way to find electrical part numbers is to look on the schematic for your serial number and find the code for the part (on mine it is D1). Then look in the back of the service manual where the electrical components are listed and find the section for your serial number and look up the code and it will list the vendor and part number. For my airplane it is listed as a 1N2483 or 1N5060 or 3720GE.

I believe the answer is that it’s not right. But, if it’s been that way for 26 years, it may not be worth fixing. In rigging, often if you change one thing you mess up another.

In the pattern in every light airplane I’ve flown I put the gear down mid-field downwind (before things get busy) and flaps down abeam the numbers when I begin a descent. On an approach, I slow to 90 KIAS before the FAF and put in 15 deg flap one dot above the GS to (get the retrimming out of the way while level) and then gear down at GS intercept which adds enough drag to start down without a power or trim change.

FWIW, Jason Hutchison at SureFly told me that they took that diagram down because it was inaccurate.

The manufacturer is required to supply a Airplane Flight Manual (AFM) specific to each airplane delivered, and the FAA must approve the AFM. The POH is a document that contains information specified in General Aviation Manufacturers Association Specification No. 1. The FAA does not approve a POH. If the POH and AFM are combined in a single document, the portions of the document that form the FAA Approved AFM must be identified. At the time that manufacturers begin using the POH format, I believe that the FAA began using the Part 23 requirements for the AFM content. According to 23.2620, for airplanes in Mooney's class, the only required content of the AFM is operating limitations. If you look closely at the M20R POH/AFM, you'll see in the page footers for Section II LIMITATIONS the words "AIRPLANE FLIGHT MANUAL FAA APPROVED." This footer does not appear in any other section and thus, Section II constitutes the entire AFM.

I would post the question on Beechtalk. Several Garmin dealers hang out there. For sure Terry Markovich would know. I’m pretty sure the answer to 1 is no and 3 is yes. Not sure about 2, but I don’t think so.

You could also contact the factory for repair instructions. I have done this for airframe repairs and Frank Crawford was very responsive.

Defined "messed up." SureFly emulates an impulse coupling mag for starting. Spark will be hotter. Should start easier.

It's only a small amount of plumbing to connect the manifold pressure line from the #4 cylinder to the SureFly SIM. Why not have it connected and try it out? You can always go to fixed timing by a simple DIP switch setting in the SIM if you don't like it.

The gear up and down switches are DPDT switches. One pole controls the relays that control the motor and one pole controls the indicators. The adjustment of the switches is critical especially on the Dukes actuator because, if not adjusted correctly, it is possible for the actuator to overrun and bend the tubes.

I'm not clear what Vno would have to do with flaps since Vno is just the maximum speed where a 30 fps vertical gust will not exceed the max load factor at gross weight.

Both apparently according to a company that makes the test panels https://www.metaspec.com/product-page/boeing-bss7434-7-1-sandwich-corrosion-test-panels

Which Part 1 definition are you referencing? The only model that Mooney ever published limits for 15-deg flaps is the 205 version of the M20J. That speed was 126 KIAS. Top of the green arc for this airplane is considerably higher at 174 KIAS.

So, there are lots of cleaning products on the market that can be used on airplanes. Looking at the SDS may give a clue to what is corrosive, but maybe not. I think it's best to use products that have passed Boeing D6-17487 which comprises four tests: Sandwich corrosion, acrylic crazing, paint softening and hydrogen embrittlement. For the sandwich corrosion test, a piece of filter paper is saturated with the cleaner and sandwiched between two sheet aluminum test pieces and placed in a humidity chamber.