EricJ

Was just gonna say, they're far enough apart in frequency to be generally separable if not orthogonal. The characterizations shown in the article demonstrate that it's fairly practical. Probably don't even need a wavelet, but if that approach works, great. Sometimes I think wavelets get used just because they make good buzzwords in the presentations or even in the marketing materials. Pretty cool, though!

Absolutely. Wing spars seem especially susceptible, and send a borescope down between the interior and the pilot's side window to check the condition of the steel tubing (plus anywhere else that's handy). If you're not seeing any paint get pushed up in spots by surface corrosion, and the inspection goes well, then you're probably in good shape. If the controls don't have a lot of slop and the rod ends don't have a lot of play, that's a good sign, too. If things have been kept lubricated it can minimize the likelihood of future failures. If your engine is running well, not using excessive oil, compressions are good, operating temperatures are good, then it's probably good to go for a while, too. There are enough piston-engine airplanes in Europe that I'd be surprised if avgas got outright banned for a long time. It might get more expensive, but it's doing that everywhere.

I do gear first for this reason, sometimes even before any power application, unless I'm too close to the ground. The gear-in-transit-up speed on my airplane is not far from instrument approach speed, and when I first got the airplane it'd blow the breaker if you tried to pull the gear up at anything over 90 knots (it's better now). On a go-around or a missed approach it made it difficult to apply full power and not pitch up excessively to keep the speed down, so I got used to either pulling the gear up first, or going to about half power, stabilizing, then gear up, then full power and deal with whatever the flaps need. There's such a variety in airplane behavior and good practice for stabilizing things that I don't think there's one rule to apply to everything.

I had an IA that I worked with before I got my IA, and even before I got my A&P we could get the entire process done in a couple days. Only a day and a half was with the IA, the first half day was me opening up the airplane and getting it ready for the inspection. As others have mentioned, a key to being able to do that is to not have any deferred maintenance. If the airplane is in good shape, the inspection shouldn't be an arduous task. And my IA was not prone to let anything slide, and wasn't even that thrilled about an owner-assisted annual other than getting some slave labor opening things up and putting it back together. It is definitely good experience for an owner, though, and I highly recommend it when the situation allows for it.

I've not used that one, but I used a couple of the other paid services when in A&P school. The FAA DRS is pretty easy to use once you figure it out, so I've not felt the need to try anything else.

I would suggest not poking the bear.

A good way to do this is to use the FAA Dynamic Regulatory System to do AD searches. It's what I use for annual inspections, etc. There are some online vids on hints to make it easy to use. https://drs.faa.gov/browse Click on ADs, then Final Rules. Under product type select Aircraft, then under Subtype select Small Airplane. Under Model select M20J. You don't need to select a Make and it's actually easier if you don't. That will give you a comprehensive AD list for M20Js. You can then go back and select Engines or Appliances or Propeller under Product Type (hit Clear first to restore the full list), and find ADs for those. You can then go through and find which ADs apply to your specific M20J and which don't. Yes, it can be a lot of work, but once you've done it once you just need to check for new ones after that.

Many ADs are specific to serial numbers and installed equipment, so there isn't going to be one spreadsheet relevant to all J models. Just fyi.

Be careful what you wish for. A re-do of the existing list could open the door for somebody claiming it is again a comprehensive list. The Coleal letter gives a lot of wiggle room for good judgement and coordination with maintenance personnel. I think that's a preferrable method.

The beauty of the Coleal letter is that it pretty much leaves what is or is not Preventive Maintenance up to the operator/owner under some very general guidelines. My takeaway has been that if you coordinate with your regular A&P/IA and if they bless you changing brake pads (for example) as preventive maintenance, I'd think you're good to go. I also think that's not an unreasonable thing to do for the reasons mentioned previously. The IA's blessing matters, since they have to sign off the condition of everything at the end of the year. A similar thing is doing "supervised" maintenance under your A&P's supervision. An A&P can "supervise" anybody doing anything and sign it off. The person doing the work should make the logbook entry with their certificate and signature, and then the A&P signs off the return to service. There is very little distance, in my opinion, between being supervised doing a brake change and doing a brake change under PM, for somebody the A&P deems competent to do so. For the PM case it's the opinion of the guy that signs off the annual that matters, so my advice is to coordinate with them, too, if they're not your regular A&P. FWIW, any maintenance is supposed to be logged in the aircraft maintenance records, so anything somebody chooses to do under PM should be recorded in the usual aircraft records with the name and certificate type and number of whoever did the work. This allows the IA to know what's up at the end of the year, and to make certain everything is okay. If you've previously coordinated with the IA, then there aren't any surprises.

My 77 J has no beacon, just strobes.

Nicely done! The pics are great.

This thing can be handy for holding adel clamps shut for installation. I've used mine a number of times and saved a fair amount of aggravation. https://www.aircraftspruce.com/catalog/topages/handeeclamp.php

dh/dl is hydraulic drop per length that the fluid travels through the media. If the input pressure is the same and the depth of the media is the same, the drop will be the same. That's why stacking filters doubles the drop, because it doubles dl. And the point of pleating is that it increases the area of the filter media within a particular volume without increasing dl. No, it doubles dl. The air gap between them is just an air gap.

What I said is correct. Apparently my error was assuming something that is intuitive to many/most would also be intuitive to you. My bad. Serializing filters doesn't increase the area. That should be intuitive, too, but I know now to give you a pass on that. Most media filter pressure drop behaviors are characterized, at least on a first order, per unit area. So you can decrease the pressure drop by increasing the area of the filter, or increase the flow rate by keeping the pressure drop constant. It's similar to a pressure drop across anything, including a hose or pipe, and increasing the area of the hose/pipe allows more flow with the same pressure. Intuitive to many, mathematically demonstrable to the skeptical, but I leave that as an exercise for the interested. There you have it. Darcy's law: Q=-K*A*(dh/dl), where Q is the volumetric flow rate, K is a measure of conductivity of the media (porosity, sort of), A is the area of the filter, and (dh/dl) is essentially the pressure drop across the filter. It's pretty trivial to see that all other things being equal, increasing the area A linearly increases the flow rate of the filter, with a constant pressure drop (dh/dl). Pleating a paper filter increases the available surface area of the media in a constant volume of filter space. Stacking one on top of the other does not increase the area, it just doubles the drop (dh/dl). That's okay. It's true whether or not you're swayed.

It's pretty trivial. Increasing the area of the filter media makes it flow better while maintaining the filtering ability. That's pretty intuitive. Paper pleats easily and allows a LOT more media area in the same filter volume than most other media, and it filters way better than cotton or oiled foam, for example, neither of which pleat well. Science!

I would suggest that it is unlikely to fly apart now due to something that they seem to be saying has been there for the last 700+ hours. I'm very skeptical of the current explanations. A case being milled past limits at an engine overhaul 700+ hours ago seems less likely than the many other explanations for what may be going on. +1 that somebody else can sign off a ferry permit.

How long had it been running before they touched it?

Those both look Very Bad. The bottom one looks to be on a component that may be replaced, but the top one looks structural.

Agreed, but given some of the information provided I wasn't going to assume that any or all of the work stated actually needed to be done. A squawk list that long for a new owner with a new airplane smells a bit too much like opportunism to me without a second opinion from somebody Mooney-competent. It may be all or mostly legit, but I certainly wouldn't assume that when presented with a large repair estimate on inspection squawks.

Valve clearance needs to be checked with the tappets dry. If they didn't remove and empty the lifters, they're going to think the pushrod is too long. Essentially all reputable engine shops have had very long lead times for years. FWIW, based on what you've said so far, and the squawk list you got from the A&P I would STRONGLY suggest that you get an A&P who is very familiar with Mooneys to provide a second opinion on everything, including the engine issues. There are a number of things on the squawk list that I think need a second set of Mooney-experienced eyes, and I suspect much of that list (if not most or maybe all) does not represent airworthiness issues. DO NOT move the data plate until further investigation. Not all Mooneys had the data plate on the tail. Some were on the nose in front of the wing, and there may have been other places as well. This is one of those things that raises a yellow (if not red) flag. I wouldn't move the data plate unless there was a compelling reason to do so. "The A&P said so" is the LEAST compelling reason to do something like that. As a new aircraft owner you should be made aware that YOU, and not the A&P, are legally responsible for the maintenance on the aircraft. Ultimately you are in charge. Don't sign up for new engine mounts until you determine that the shims have been adjusted the maximum amount for any droop that may or may not be happening. Bottom line, I'd stop everything and get a 2nd opinion from an experienced Mooney mechanic. There are too many big questions about what you've described so far.

If you have maintenance records back a full year, AD history, STC paperwork, etc., basically everything that is actually required by the regs, then you aren't missing anything. The only place where "missing records" creates an issue is with a buyer using it to try to negotiate a reduced price from a seller. It is strictly a percieved value issue. If you have the records required by regulation, everything else is just used for negotiation, so do with it what you will. As already mentioned, that page may have been taken out due to a coffee spill or whatever other reason. If you're basing all of this on input from your current A&P, you're only hearing one side of the story. You'd probably hear something completely different from the other A&P. Don't get caught in the middle or to one side. This can happen to a new aircraft owner and it can wind up being very expensive if you don't take your time, proceed slowly, and get additional opinions. GA airplane alternators are often based on automotive alternators (if not direct appropriations) and if the installation on your airplane is an STC it is possible that you have the correct alternator. As you were previously advised, look at any relevant STCs before making too many conclusions.

What are the dates on the surrounding pages? Records older than a year are not required to be kept. There is no regulatory requirement to keep maintenance records older than one year. Records are also not required to be kept in "logbooks" or even in paper or whatever. The records that are required are just required to be kept as records. They can be written on used napkins as far as the regs are concerned. If the record was older than a year I don't know what basis you'd have for pursuing action against anyone.

That's a screaming deal on some quality jacks. I'm surprised they haven't disappeared already.

A G5 is a very good instrument and a good addition if you have a GPS navigator. My G5 HSI was installed not long after my DG failed, and later after several AI failures I punted and put in a second G5 to replace the AI. I highly recommend them. I've flown with GI-275s as well, and while they certainly have their place, I think the display space on the G5 is used much more efficiently and is more readable than the 275. I'd suggest getting a good look at both before making a decision.