PT20J

Sectional chart got me in the C.

Short for variometer another name for VSI, but the type used in gliders is more sensitive. An IVSI is a VSI aided by a mechanical accelerometer to reduce instrument lag.

Something is not right. It looks like there may also be a longer vertical crack under the paint. I would definitely figure this out and fix it before it damages the vertical stab as that might be a very expensive repair.

Curtiss Valve, Saf-Air make compatible valves. The spring in the Saf-Air is pretty stiff making sumping more difficult. Don’t overtighten when installing.

It’s got to be aerodynamic. The only CG change would be the forward movement of the nose gear and that cannot be very significant. Also, I would think that a CG change would cause a need to retrim and this just seems to be a transient effect while the gear is in motion.

My 28v M20J has a 10A cb, no fuse, and no dropping resistor to the original cigar lighter. If it is not in the schematic I would remove it. The cb protects the wire.

You might order a couple of cans and paint a couple of pieces of cardboard (foamcore works great) to see what you like. It’s hard to tell from the little color swatches and if you are only looking at it online it is impossible because of the variations in screen color rendering. Sailcloth is very bright white. I used Phantom white which is close to the original off white color.

On the M20J, there is a transitory pitch up moment during gear extension that disappears when the gear is fully down.

I agree with Don. The avionics shop probably wants to start with all new parts because it reduces any chance of issues with existing components. The antennas are not very expensive and once you select a shop it's best not to tell them how to run their business. But, the OP asked if replacing the antenna was necessary and the answer is no, if it is working correctly.

The install manual for my GTX 345 states that the antenna is considered part of existing equipment and that any antenna approved toTSO-C66() or C74() is acceptable. We reused the original King antenna from the KT 76A and it works fine.

If you believe that, you might also want to replace all your nav/com antennas as they also have BNC connectors. But if your BNC connector is truly "crusty" with visible corrosion, then that's a different matter.

For those that like landing with the speed brakes deployed, what to you raise first on a go around?

A lot of problems can be avoided by making the decision to go around early when there is still sufficient airspeed and altitude that technique isn't critical. If you have to go around during the flare it gets much more dicey. For those interested, here are the aerodynamic coefficient curves for a M20K clean and full flaps that I got from a Mooney engineer many years ago. I don't have one for takeoff flaps. M20K Aerodynamic Coef - Flaps 0.pdf M20K Aerodynamic Coef - Flaps 33.pdf

The STC installation manual should have a list of approved antennas.

I repeated Don's experiment in my M20J MSE at 2500' and an initial speed of 100KIAS. Gear down reduced airspeed to 77 KIAS, flaps full down 78 KIAS, gear and flaps both 70 KIAS. So gear and flaps were approximately the same with a 23 KIAS reduction. One of the issues with Mooneys is that the control forces can be higher than many other airplanes of similar size and weight. Sometimes you have to push or pull pretty hard to make the airplane go where you want it to go until you get it back in trim. There is nothing wrong with using two hands on the yoke if that's what it takes. If you check the stall speed table in the POH, you'll notice that Mooney flaps reduce stall speed more than most other comparable airplanes. But, most of the stall speed reduction comes from extending full flaps. The takeoff flap setting mainly changes the deck angle and adds a little drag.

Insurance cost comparisons are meaningless unless you state the insured hull value and the liability limit including whether it is “smooth” or has a sublimit.

General practice is that the ALT breaker size is determined by the wire size between the breaker and the alternator and the wire/breaker should carry more current than the alternator can put out. Thus, the ALT breaker can never trip with a good alternator. The ALT breaker is there to protect the wiring between the breaker and the alternator in case there is a short because the battery can supply much more current than the alternator.

Your GTP 59 temperature probe connects to the G5 ADAHRS. The G5 ADAHRS should output the temperature data on the CAN Bus to be shared with other units. IF the GI 275 is connected to the CAN Bus, it may be able to get the temperature data. It all depends on if Garmin has the software set up to do this with the GI 275 is configured as an EIS. I would discuss it with a Garmin Dealer that really understands this stuff (not all do). Additionally, the dealers have access to a field support team that is often more knowledgeable about special configurations than the customer-facing support team.

According to the IO-360 graph in the Operator’s Manual, an IO-360-A should burn a little over 15 gph at full power at best power mixture. It burns more during takeoff because it needs additional fuel for cooling. Mine burns a little over 18 gph.

Camloc prices have gone through the roof. A couple of things to note. First, stainless is softer than carbon steel and will deform more easily if the studs are too short. Second, if you look closely at the picture posted above, the pins appear bent slightly and the holes are elongated indicating that they were too tight. I had the same thing happen after painting and all of mine that had the pins come out were too tight.

According to my painter, aircraft polyurethane is more flexible and applied thicker than auto paint.

I think the only additive Lycoming approves is LW-16702 which is TPP.

I wonder what the real difference is between inexpensive products available to consumers and the more expensive products only sold to professionals and if the extra cost of professional application is really worth it. If the consumer products are easy to apply in a couple of hours and last a year, that seems pretty reasonable to me unless the paint is in bad shape and needs professional correction first.

Traditionally, Lycoming did not produce maintenance manuals and instead provided maintenance information in service letters, instructions, and bulletins. Recently, it has begun producing maintenance manuals for some engines. There does not appear to be a maintenance manual for a TIO-540 https://www.lycoming.com/sites/default/files/attachments/SL-L114BJ_Technical_Publications.pdf.pdf

A couple of years ago, I noticed the compression on one cylinder on my Lycoming IO-360-A3B6 was trending downward on successive measurements from 78 to 74 to 68. I added Marvel Mystery Oil to the fuel for a couple of tanks and the next time I checked the compression, it was 76. Might have been a coincidence. Recently, I had a cylinder drop out immediately after cold engine start. It happened again the next day. Maybe a valve beginning to stick? I added Marvel Mystery Oil to the fuel for one tank full and haven't had the problem since. Again, it might have been a coincidence. A local mechanic swears that it makes a great ring flush. Supposedly a lot of DC-3 operators used it to prevent valve sticking in R-1830s back in the day. The mechanic at a museum where I used to volunteer told me that back when the FAA operated several DC-3s as flight check airplanes a mechanic that serviced them told him that it was used it in these planes for the same reason. Apparently they bought it it 55 gallon drums. What's in the stuff? I've attached the SDS. It's Petroleum distillates, hydrotreated light (solvent), Methyl salicylate (wintergreen fragrance), TCP, and two isomers of Dichlorobenzene. TCP is a known lead scavenger. Some searching shows that dichlorobenzene might soften carbon and varnish deposits. So, theoretically it might be beneficial. I don't know, but I'm curious what others have experienced. MM12R_50094_MM13R_50095_MM13RC_Marvel_Mystery_Oil_SDS_US_031424_FINAL.pdf