EricJ

The 2017 AD applies to a smaller subset of engines than the 2024 AD. You only need to comply (or assure compliance has been done) on your engine for that AD if it is covered by the 2017 AD. If it is, then you need to comply with the 2017 AD. You only need to comply with the 2024 AD if it is covered by that, which is a broader category (and a bit more ambiguous), than the 2017 AD. If you engine is covered by both, you need to comply with both. Compliance with the first (2017) may be terminating for the 2nd if parts were installed that are not covered by the 2024 AD.

Nice job on the repair! Mine are UV filtering and in AZ it makes a huge difference in keeping the cabin from turning into a furnace. Definitely worth it if the airplane sits in the sun very much, imho.

The o-ring is the seal against the bottom of the wing and the nut plate that is riveted to the wing skin inside the tank. The nut plate and the rivets that hold it are sealed with tank sealant on the inside just like the rest of the tank. If the drain valve gets overtorqued on installation or it gets broken or stuck and needs a lot of torque to remove it, it can move the nut plate enough to slightly unseat the rivets and/or lift some of the sealant inside the tank. That can lead to some annoying leaks (both of mine did this). On mine the leaks are around the rivets that hold the nut plate in. Both of mine responded well to liberal application of oyl-tite seal, swiping it across the rivet heads to try to drive the seal stick material under the rivet head. One side I've had to re-apply it once after a couple years. Other than that they've stayed pretty tight and leak very little. Otherwise a "proper" repair requires resetting the rivets, which requires removing the seal inside the tank around the nutplate and resealing it after either replacing or resetting the rivets. It's the sort of thing that is done during a tank reseal or repair but I think is otherwise not the first option.

So does the STC stay with the engine or the airframe if they're separated? I'm puzzling a bit about the need for the plate on the engine.

If it was me, I'd contact Hyfast and see if those rods contained the affected bushing.

Nice! I have a bunch of pics I took of it when it was sitting at Winslow, and I'm glad you got it back flying! It looked like it had good potential. Looks much better now!

That was my first read, that it intends to address engines shipped from Lycoming. However, it doesn't say that explicitly, and leaves a lot to interpretation. It could be read that it was intended to include anything assembled in the field during the specified times with the listed part numbers. I don't know why the assembly date would drive, though, as one would think the batch of the intalled part would be more important. I think the bottom line is that it is just a very poorly written AD. Regardless of how the AD is disposed in your logbook, I think it'll be worthwhile to pay attention to your filter media for bronze chips for a while.

Yes, licensing deals for developed technology is something I'm very familiar with. I'm also familiar with developers wanting to get paid up front, especially when it looks like their product may not be successful or gain sufficient market share to provide an ROI. BTDT, got a bunch of t-shirts. Business is hard.

Yeah, it's not straightforward. My engine was originally built well outside the covered date ranges, but got an IRAN in 2015. I looked up the IRAN record and none of the affected parts were on the part list, and there was no indication that the bushings were touched. Seems like an NA to me.

There isn't any official FAA document that is a "yellow tag". There are 8130-3 documents, that are only necessary if you want to export a part. An A&P just needs to make sure it's airworthy for installation. There aren't really any test requirements for a VSI to define what "airworthy" means, but I think if it doesn't cause any leaks in the rest of your static system (which does get tested via the usual leak test), then it's at least airworthy. Your existing VSI never gets calibrated during static/leak/altimeter tests, other than to keep from overrunning it during the test. A test fixture, or even something as simple as a syringe, can verify that the instrument is at least functional. I have an air instrument tester that I got off ebay and rehabilitated that works great for that sort of thing and that I use to do static/leak tests for airspeed indicators, altimeters, etc., and also VSI. My tester isn't calibrated, but it's certainly good enough to verify air instruments are functional, and will make sure a VSI isn't completely out of whack. Even just testing a VSI with a syringe and piece of tubing will let you know that it's working, but it won't be calibrated. There isn't really any requirement to calibrate VSIs, though.

I don't see a requirement for spectrographic analysis, just a visual inspection of the filter media for bronze particles.

If you don't have the override switch you likely still have the squat switch, which could be contributing to the problem. A common modification is to replace the squat swith with an airspeed switch that has the override button. Mooney used to supply a kit to do that, they may still be able to.

I think the lingering questions are not whether the STC covers everything, but whether it is actually a sufficient drop-in substitute. That won't be known until there is an awful lot more field data.

They have a patent on the fuel, so it cannot be produced without a license from GAMI. STCs shouldn't be necessary to recoup their investment if the fuel is successful.

To answer your question, yes, spar cap issues are not unusual for Mooneys that have been in salt air or other corrosive environments. It can be repaired, but whether it makes economic sense to do so or to find a replacement wing may depend on some details. I agree that the pics aren't great, and having somebody competent inspect it may be able to determine what is happening there. Can't tell much from the pic, but often a bulge like that is a bad sign.

There's nothing special about the motor itself. Most electric motor shops should be able to work on it.

Something isn't right (obviously). The motor is on if the unsafe lamp is on, and doesn't turn off until the gear is fully up. If the gear has jammed and prevented the motor from running the gear all the way up, one would expect the breaker to pop. If the breaker doesn't pop, I suspect the brushes in the motor may be getting tired and need to be replaced, or there is a potential wiring issue that is limiting the current.

Drilling polycarbonate or acrylic needs to be done carefully to prevent cracking the piece, but there are some methods that work well to mitigate that risk. YT vids are your friend for this. Trimming can be a little tricky, too. The techniques are not difficult or hard to learn, though. IMHO it is something you can do yourself, but talk to your A&P/IA first since they sign off your annual.

Yes, they shorten the props. The F1 guys do the same and spin the O-200s faster for more power and shorten the prop.

I think for Mooneys those are almost always Johnson bars that popped out of a worn downlock block.

Not at the bearing surfaces or other areas when it is running, it is much higher than that. That's the temperature when it is entering the engine, it's much hotter when it returns to the sump.

The engine is vented to atmosphere via the vent and naturally pressurizes a bit. That's how the oil mist from the crank windage winds up on the belly, and how you can lose a quart via fine mist going out the vent in not very much time if it is overfilled. It's also why many vent tubes have an ice hole, so that if ice plugs the end of the vent tube the crank pressure doesn't blow the main seal out. So the motor is actively moving gas through the crankcase, some more than others depending on the amount of blow-by. That's the mechanism by which it exchanges the existing moisture content, which may be elevated by accumulated condensation, for a lower level. After shutdown as the engine and case cool it'll draw ambient air in through the vent which can reduce the moisture concentration further. Again, the idea is that if there is a lot of moisture in the engine from accumulated condensation, that moisture level can be significantly reduced by running the engine up to temperature so that it vaporizes and can be driven out the vent. The active dehumidifier systems are intended to do the same, but don't refresh the oil films to protect parts, and don't address the moisture in the oil. They certainly can help to keep moisture off of internal surfaces, though. If one can't or doesn't want to run the engine, removing a set of plugs and motoring it with the starter will at least refresh the oil film on the important parts. That doesn't reach the same pressure as when running, and doesn't spray the oil mist from the crank windage around like running it does, but it at least gets the bearings and other surfaces refreshed. It certainly isn't required. People have been leaving engines sit for long periods since engines were invented. It is sometimes fatal to the engine, sometimes not. People have been running engines periodically for preservation since engines were invented. It is a continuing practice due to the historic success compared to neglecting an engine. YMMV, everybody does what they think best within their capabilities and circumstance.

One of my race cars was an RX-7 that sort of fell on me after a buddy got it as payment from somebody that owed him money. It was already prepped as a race car and I think I ran it for about a year after we got it going the way we wanted it...or as much as we could, anyway. The engine was reliable, but they make very little torque. I'd race with the Porsche 944s and if I was careful I could get off the corners and ahead of them on a corner exit, but once I shifted into 4th gear they'd just disappear down the straight. There are advantages and disadvantages to the rotaries, but the disadvantages are significant enough that they've not really caught on anywhere, especially in Aviation. Moller spent a bunch of investor money "optimizing" rotaries for the Moller Sky Car (remember those?), and they were so successful that after forty years there are still no Moller Sky Cars flying. They apparently market the motors now for whoever will buy them: https://freedom-motors.com/ And the SkyCar is still evolving into new hybrid versions, with rotary motors. So rotary motors are good for vaporware because they do kinda look good on paper.

From a radio perspective they're fairly primitive, same with marker beacons and the AN airways. A VOR is a more interesting beast, and one of the interesting things there is that the implementations of the transmitters evolved over time from mechanically-modulated to a few interesting generations of advancing electronic implementation, and they all stayed 100% compatible along the way. It's still not a bad way to do things to accomplish that task, likewise with an ILS.

The Dynon and IFD package sounds pretty awesome, actually.