PT20J

Charlie Munger once said, "All I want to know is where I will die so I'll never go there." I tried looking for someplace where airplanes don't crash so I could move there, but according to this app, it's hopeless.

Mooney used Radio Shack speakers. The little convex mirror that deflects the wing-mounted taxi light beam away from the cockpit is from K-Mart. So, even with all it's business troubles, Mooney has outlasted two of it's much larger suppliers .

I don't have M20S manuals. My M20J parts manual shows the Blaupunkt PCX352 as an alternate for the Archer 40-1197. So, either should work electrically. Since the OP's picture is of a Blaupunkt, I would search for a 3.5" speaker as a replacement. Regarding the impedance: If the amp will drive a 4 ohm, it will drive an 8 ohm because the higher impedance will require less drive current. The 8 ohm might not be quite as loud, but I doubt it would be noticeable and since Mooney apparently used 4 and 8 ohm speakers interchangeably I wouldn't worry about it.

Better yet, if you can find an accommodating A&P, you can do all the paperwork, download the software and have the A&P look over your shoulder when you install it and then sign the logbook. The G3X update is not supposed to alter any configuration parameters. However, I've been told that some GTN updates can change configuration parameters that are not stored in the configuration module and so the instructions call for verifying the configuration after installation. I wonder how many shops do that? There are a LOT of configuration parameters for my GTN 650Xi.

I've found that sometimes you have to hunt for the an electrical part number. Sometimes they are in the IPC. But, it's often better to get out the schematic for your serial number and note the component reference designator and then look that up in the Electrical Equipment Chart for your serial number at the end of volume 1 of the Service and Maintenance Manual. I say this is better because if Mooney used different parts on different models, the service manual will often be more accurate than the IPC. Here's a link for the original speaker listed in the M20J IPC (Archer 40-1197). It's is a pretty standard 4", 8 ohm speaker. https://diyaudioprojects.com/Drivers/40-1197/40-1197.htm Searching the service manual, Mooney used several other Radio Shack (Archer) speakers, but I'm betting they were all equivalent. (Perhaps they just used whatever the Kerrville Radio Shack had in stock when they needed some ).

I replied to the email with the following question: If Garmin does not issue a service bulletin, how will I know when a software update is available so that I can take the airplane to my Garmin dealer to have it installed? I must have caught support on a slow day because I got a reply right away: Not every software update requires the issuance of a bulletin. Not every software update is required either. I would recommend you stay in touch with your Garmin Dealer. Due to the nature of certified software, software updates only happen once or twice a year. Most customers update their software once a year unless a major software update was released. Major updates normally do have a bulletin. So, I guess if Garmin thinks it is important, it issues a service bulletin which should come in the email if you are signed up. This might be a ploy to avoid customers complaining about the cost of installing Garmin's frequent updates. Even though Garmin makes the software available at no charge, Garmin dealers need to charge for installing it, printing out any accompanying documentation and making the logbook entry.

I just received an answer from Garmin regarding the lack of service bulletins for recent G3X certified updates. It's not very satisfying or illuminating: Bulletins are not always released for the G3x Touch Certified Software. The last two releases 9.16 and 9.17 only describe the changes as "General improvements to system operation", whatever that means. I suspect that Garmin is only issuing a Service Bulletin when a release fixes a problem noted in an earlier bulletin or introduces some new feature -- but that's just a guess. Garmin's software management system defies understanding.

I'm not too concerned about the Mooney. Now, when we used to jack up the DC-3 at the museum to swing the gear -- that always got my attention.

I once preflighted a Schweizer 300 after it came out of maintenance and found all three pitch links unsafetied. I don't know what the answer is other than to be as hands on with maintenance as possible.

Yes, but it will ignite when I lock the brakes trying to make the first turnoff and wear through the tire.

I don’t know which interior you have. In mine the lower panels are carpeted and installed first before the side panels so it requires taking the side panels off first.

Yes, they both come from the same tone generator. Steady tone for the stall; on-off tone for gear.

Fill with helium and get a useful load increase (Wonder if landings bounce more, though)

You don't really need a picture -- the inboard senders are behind the lower trim panels. Once you get those removed the senders are obvious.

You are correct. Attached is the Mooney Service Instruction. sim20-59a.pdf

Air is mostly nitrogen and the idea as I understand it is that the other substances in the air leak out faster than the nitrogen. But, every time you add air you'd be increasing the nitrogen concentration and it seems that eventually you'd have all nitrogen anyway.

If tapping the covers causes them to light, the problem has to be either the bulb or the bulb holder. I’d remove the covers and bulbs and spray the holders with some contact cleaner and then insert and remove the bulbs several times to clean the contacts.

Earlier Mooneys used sonalerts for stall warning and landing gear warning. Later models used a tone generator driving a speaker. I’d double check the size, but I think it’s just a common 4 inch, 8 ohm speaker.

Not a bad idea. My 1994 M20J came with heat shrink around the tubes at the points where they go through the holes.

That’s normal. Just make sure the grommets are in good shape to prevent wearing a groove in the tube and put some grease on them at annual.

80/80 is kind of hard to get because there should be gaps in the rings. An old auto maintenance trick to determine if the rings are leaking is to squirt oil in the cylinders and see if the compression improves because the oil seals the rings. I might try letting the engine sit a day or so and then do a cold compression test. We did a lot of cold compression tests at the museum because it was a lot of work to tug several large aircraft out of the hangar to get one out on the ramp to run it. If the compression was low, we'd repeat the test hot. We never noticed much difference cold compared to hot on a good jug. At the Lycoming factory school they said not to be concerned with scratches in the cylinder walls if you can see the cross hatch through them. The leak down compression test mainly tests rings and valves. To check cylinder condition, the instructor suggested doing an automotive style pressure test because the piston travels the entire length of the cylinder to generate the pressure. For an IO-360 the quoted pressures were 155 psi (new), 140 psi (mid-life) and 120 psi (worn out).

Yeah, it's like most refer to the part of the nose gear that gets damaged as the truss when it's actually the leg.

Greg Baker told me that the problem with the servos was a bad mechanical part - a bearing if I recall correctly. So, it’s probably dead.

I doubt that the holes in the channel would line up with the zerk. I believe that's the purpose of the channel - to route grease from the zerk to the holes that allow grease to flow from the channel to the bearing surfaces. @N201MKTurbo probably knows for sure.

If you get a drawing and material specs, perhaps the best solution is a smallish machine shop. It sounds like the specialty gear manufactures are not interested in making a small run of parts once.