PT20J

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.

Are you really sure it is spun? Those bushings are pressed in and to spin it would take a lot of torque. I've found that partially raising the gear and moving the main wheels up and down with one hand while operating the grease gun with the other will often get a troublesome zerk to take grease.

It appears from the example in the Concorde document and Eric’s experience that these things go from good to bad rather rapidly. Maybe it’s just smart to just replace every 4 or 5 years if you fly IFR in a predominantly electric airplane.

Do you have pictures?

I’d contact Frank Crawford at Mooney. fcrawford@mooney.com

I emailed my Lycoming rep and got this reply: "If it is the video I’m thinking of, it was posted by a company that used our video content without our permission and generated captions throughout that was spreading inaccurate information. All videos posted directly from our page have the accurate and Lycoming specific information that was falsely discussed in that video, please enjoy any of our uploads! Thank you for reaching out." Lycoming's Youtube page is: https://www.youtube.com/user/LycomingEngines

Also keep in mind to quote W. Edwards Deming, "There is variation in everything." Some batteries are just going to last longer than others. Everything is on a bell shaped curve.

The answer, as you might expect, is, “It depends.”

It turns out that Concorde has Technical Bulletins discussing adjusting capacity check intervals and maintenance charging. https://www.concordebattery.com/knowledge-base.html?media=tb

Thanks, I should have mentioned that.

Agreed, but not that hard if you charge it immediately after the test. It’s a tradeoff. I wouldn’t do it monthly. But maybe 6 month intervals would make sense.

I think most building codes only require gas water heaters to be 18” above the floor due to the pilot light. Seems like requiring the refrigerator to be 18” off the floor is overkill, but my hangar has that reg also.

I think the idea is that if someone has a fuel leak, the fuel vapors are heavier than air and so will be near the ground. So, keeping any potential spark producing equipment 18" above the floor might prevent ignition.