mooniac15u

Here's the whole chart.

The M20J has a Vso of 55 KIAS and, in the corresponding chart of stall speed vs bank, a stall speed of 54 KIAS in landing configuration. I guess it doesn't have a 5 knot uncontrollable "dead zone" like the M20E.

Both Vso and the ASI white arc were well defined under CAR 3 and meant the same thing as they do today. You can find the definitions in sections 3.82 and 3.757.

It's that bumpy runway at OSU. They just resurfaced the runway at TZR. You probably wouldn't have the shimmy if you were still based there.

I thought you had already purchased a used unit.

The FAA is decommissioning 308 VORs and effectively relegating VORs to a backup navigation status. https://www.aopa.org/news-and-media/all-news/2016/july/26/faa-releases-vor-policy It will become increasingly difficult to operate in the IFR system without a certified GPS.

M20J. It isn't a restriction (red arc), it's a caution (yellow arc).

It is interesting to note that the M20A-F models (with certain props) have a RED arc on the tach and the M20J has a YELLOW arc on the tach. The notes in the TCDS describe a "restriction" versus a "caution." The following notes are from the TCDS. For the M20A-F: "Engine tachometer is to be marked with RED arc between 2000 and 2250 RPM indicating the restriction against continuous engine operating in this speed range for M20A, M20B, M20C, M20D, M20G models with Hartzell HC-C2YK-1/7666 propellers or HC-C2YK-1B/7666A-() propellers." "Engine tachometer is to be marked with a RED arc between 2000 and 2350 RPM indicating the restriction against continuous engine operating in this speed range for M20E and M20F only." For the M20J: "Engine tachometer is to be marked with a YELLOW arc between 1600 and 1950 RPM indicating a caution range against continuous operation in this speed range with manifold pressure below 15" Hg"

Sample contamination is always a possibility. How did you sample? What kind of container was used? Was it in any other container or tubing between the engine and the sample vial? Do you use any oil additives?

California definitely has a reputation for being over the top in banning things. However, chromium (VI) is actually a serious carcinogen. You would be better off avoiding chromium compounds.

On your J the sensor is essentially just a variable resistor with a spring. As the pressure changes the contact point changes and the reading on the gauge changes. Since the fuel pressure sits at about the same place most of the time the contact at that point starts to go bad. Then small changes can make it jump around. I just replaced the sensor on my 1981 J for the same reason. The gauge is now steady.

Hydrogen and Oxygen will not normally spontaneously combine to make water. That would require combustion inside your tire. Water vapor already present in the air complicates things because it can change state in the temperature and pressure ranges we are talking about. That changes the amount of gas present in the tire which will impact the pressure.

You must not live somewhere with significant seasonal changes. Nitrogen pressure in your tires will change about 1 psi for every 10 deg F change in temperature.

Water vapor, yes. Nitrogen, no. Anyone who claims otherwise has an incorrect understanding of the physics of gases.

It's a wingtip mounted ADS-B transponder. https://www.uavionix.com/products/skybeacon/

The pressure of Nitrogen, Oxygen, and regular air all exhibit nearly identical behavior with changes in temperature. The compressibility factors of Nitrogen and Oxygen at 70 degrees F and 1 atm are 0.9998 and 0.9993 respectively. The changes in pressure of any of these gases or mixtures will vary with temperature according to the ideal gas law (PV=nRT). A tire pressure gauge would not be precise enough to measure the difference in pressure changes between Nitrogen and air over seasonal temperature differences.

Departure stalls on go-arounds have gotten low time pilots in many different types of aircraft. The risk is real and more so in a Mooney than most trainers. Using less trim on short final helps mitigate that risk.

If you have full nose up trim on final and apply power to go around it can cause the nose to pitch up significantly. It can potentially be a dangerous situation if you aren't prepared for it.

With bulbs I think the parts catalog also specifies the approved part number even though it's just a standard part. Kind of like fasteners. If the LED bulb is a different part number then I guess it would need some kind of approval basis.

It seems like it might come down to materials vs parts. The fiberglass and epoxy are materials used to repair a part. The items in question have part numbers in the Mooney and Lycoming parts catalogs. When replacing a part you need some kind of approval basis for the new part. Usually that's a PMA. I think the problem here is that it seems a little heavy-handed to call a piece of silicone a "part" in the same way that a flap is a part.

I saw this on BeechTalk and it lists Mooneys so I'm just posting it here as an FYI. I know a lot of folks here are very happy with the quality of products from this supplier but apparently there are some unresolved issues with the FAA. https://www.faa.gov/aircraft/safety/programs/sups/upn/media/2017/2017_98_071R.pdf

Without damage to other, more important, structural parts? If it hit hard enough to damage the shock discs I would be worried about what else might be bent or cracked?

Why would a hard landing necessitate replacing the gear doors and shock discs?

I could guess but it probably wouldn't be any better than your guess. I have a Ph.D. In chemistry so I can discuss ideal gas behavior all day but my expertise is mostly theoretical. Maybe one of the engineers around here can comment on the real world application.

Conpressibility factor is not significant for either nitrogen or oxygen as both are non-polar and non-associating. The ideal gas law provides a reasonable representation of how they behave under temperature changes.