AndreiC

Forgot to attach the interconnect diagram.

I recently pulled out my perfectly functioning STEC 30 autopilot head from the panel (to gain access to the DG) and when I put it back in it failed to start up. When I checked the connector, it turns out I had bent two pins. However, even after straightening out the two pins and making sure they now go in correctly, still the A/P does not start up. What it does is that the gyro is spinning up as it should, and when I flick on the A/P switch I can hear the servo in the back go through the motions, but I get no lights on the autopilot face to light up. One other thing -- when I opened up the connector to inspect it, there is one loose black wire that I suspect is a ground that appears to have been disconnected. But I don't know if this has been like this for a long time, or it is from me messing around with it. A local avionics shop offered me to put together a small harness with just two powers and two grounds (for the A/P and for the gyro, which are independent) and see if it lights up on their bench. My question -- do you guys know if these autopilots show any signs of life (like lights coming on) before they go through their self-test? Would the test proposed by the avionics guys show me anything, or is it the case that if the system does not power up on their bench it means nothing (like, it went through self test and did not find responsive servos, etc. so it shows nothing?) Another question -- I attach here the interconnect diagram I have found for the STEC 30 autopilot. Can you guys tell which one is the autopilot ground connection? Is it the main one on pin 34, or is that just a safety grounding pin and there is something else going on? If I were to take a wild guess, I'd assume that the autopilot head is not getting power (but the pitch computer is, hence I can hear the trim servo being initialized), and the most natural guess would be that the ground line (the black line I found in the connector) is disconnected. But when I checked the connector, there definitely is a black wire going to pin 34. Thanks.

Also, flying above a class B should not be an issue for an F. The top of O’Hare’s class B is at 10k. I’ve had my NA E model at 16500 and would have had no issues climbing further. (True, I was alone, but with a decent amount of baggage and full tanks.)

Somehow, I don’t know how, I managed to put an unpleasant scratch in my windshield. It is an area of maybe 1/2” x 1/2” that is now hazy, and if you feel it with your finger you can clearly feel it’s not smooth (it’s on the outside). Can something like this be polished out without messing up the whole windshield? I can live with it as it is, but it is in my field of vision and it will bother me every time I fly. But replacing the whole windshield (which probably is at least a 1 AMU endeavor, if not more) sounds stupid for such a small scratch. I was hoping that maybe the kind of treatment that removes haze from car headlights would fix it. But I don’t know if it works, if it does not make it worse, and if I can do it in just one localized spot or if I need to polish the whole windshield.

I am using Aviation Insurance Resources, (301) 682-6200. Victoria Neuville is my agent and I have been happy with what she finds for me. Have been using them for 15 years at least. When I moved to Mooney two years ago (after a long time in Cherokees) that got me insured for $2715 with only 5 hours in make and model, hull value of $85k. But I did already have over 1200 hours, instrument rated, and had over 150 hours in retractable gear (Comanche, long time ago). After one year and crossing the 100 hours in M&M the insurance price dropped to $2041 on hull value of $90k.

I'm interested to hear more about this. My plane has an ancient King KA-134 audio panel, and I am concerned that sometimes after you use the speaker button the audio panel loses all functionality (the audio from the radios goes neither to the headsets nor to the speaker). Lately I decided to never use the speaker button any more. I was thinking of getting a PMA7000BT installed in its place. I think the extra 1/3" can be found somewhere above, without having to move the entire stack. (The KA134 is 1" tall, while the PMA is 1.33".) My question is to what extent this is something that can be done by my A&P, with my help, instead of having to go to an expensive avionics shop; and also if it is possible to do the work in two stages, a first one that only involves installing the new tray and rewiring the plugs in the back, while reusing the mono wires that go to the headset plugs, and a second stage replacing the headset wires and plugs. Does any of this make any sense? The problem is that my avionics shop quoted 2.5-3 AMU for a complete install of a nice audio panel...

The instructor who did my Mooney transition training (ex-official Mooney factory instructor) advised me to use the round hole of the front landing gear to attach the ground, and I've been doing this ever since. (I mean the sides of the hole where you insert the towbar into the front gear.)

If you were at 4500 you should be able to get around a 25" MP maximum. (At sea level the pressure is more or less 30" -- standard is 29.92" -- and you lose 1" of MP for every 1000' of altitude. This is not precise, as the engine is not 100% efficient, but should be close enough.) Certainly 19" is very low. Is your throttle control rigged properly? If that is correct, then the culprit could be the MP gauge itself.

What I do not understand is -- if you already have $225k ready to pay for an airplane, why not buy a really nice MSE that has a low-time engine and good avionics? There are quite a few on Controller around $200k. Then you have your plane ready to go on day one. The only downsides of that plan I can see are -- 1) you don't control the overhaul process, and don't get a warranty on the engine; and 2) the panel you get is not exactly what you want. For me, not having the plane down for a year or more for maintenance would be more important. But everyone's priorities are different.

I am happy to put as much elbow grease into polishing/buffing the plane as I can, but every time I tried to do it the results have been disappointing. I don't know if it is my technique, the materials I use, or the fact that maybe my paint is shot. One option of course will be to just go to the guys that quoted me 5 AMU and let them do a small patch, observe what they do and how they do it, and see if I can do it myself (or if not, have them do it). One thing I was trying to gauge on the list here is if the 5 AMU price was within the normal range (given that someone said 2 AMU it seems to have gone up a lot, or that this place is really pricey), and what people thought, if 5 AMU was worth it or not.

I just saw the offer below from a company affiliated with Amazon, so presumably it is not a flaky one. I was wondering if this appliance could easily be adapted to push/pull a Mooney in/out of a hangar. What do you guys think? https://tools.woot.com/offers/superhandy-electric-trailer-dolly-14?ref=cnt_wp_0_27&fbclid=IwY2xjawG8BKNleHRuA2FlbQIxMQABHdiXibls7qtKarO_TRA6sBnI_Z4_F-ZGlGwzFAoSvkDhfg0abvYzF7quqQ_aem__gttZBtgh2uMc7lFdyfaoQ

I have been thinking about hiring a professional to do a two-stage paint correction (i.e., buffing) and ceramic coating of my plane, a 1970 M20E. My plane was last painted some time in the 1990's, and while the paint is all there and not chipping away, it is not exactly shining either. However, after talking yesterday to a guy recommended by @Sabremech, I was a bit taken aback by the price. They said to do the whole plane is going to be 5 AMU, and the ceramic coat will last about 2 years, after which one would need to reapply it (but no need for buffing again) at a cost of about 2.5 AMU. I had thought the cost should be closer to 3 AMU for the whole job, and maybe 1 AMU every two years. I was hoping to get some opinions from people here who have done it, and whether they thought it was worth it. With a paint job costing north of 25 AMU these days, I don't see re painting my plane any time soon. Also, another question. Can I perhaps ask them to only do the visible parts of the plane (i.e., no belly or underside of the wings), since I never look at how shiny the plane is underneath? That would be only about half the work, right?

My impression is that our engines fail in two ways. One is that they start making metal, eating themselves up relatively slowly. This kind of failure is easy to detect with oil filter inspections. Maybe to be on the safer side one would do more frequent oil changes on an engine that is past TBO (perhaps every 25 hours including the oil filter), at least in the beginning until one gets to know the specific engine. Possibly, and here from what I read the opinions vary on the usefulness, you could also send oil samples to a lab to be analyzed, and after 3-4 oil changes you could start to see trends in metals that appear in the oil change. (My understanding is that one oil analysis is useless, as the absolute numbers are not that important; more important are the trends over time.) But my understanding is that from the time the engine starts making detectable metal, it won't die catastrophically within 25 hours, so you'll catch this kind of issue in time (but head for an overhaul once it happens). The other kind of failure is the catastrophic failure: engine throws a rod or seizes up due to oil not reaching a critical part. My impression (and, again, I am not a mechanic so don't count on my opinion as being worth much) is that these kinds of things happen more from an improperly assembled engine (or one that is improperly operated -- for example if you get detonation) than from the engine being old. This is the "infant mortality" phenomenon. This is why people like engines with around 500 hours, since they proved already to be woking well. My understanding is that as you get past TBO, especially with an engine that has not been run much in the last few years, the odds of starting to make metal increase. One reason for this would be if the camshaft starts getting pitted from corrosion. (The cam in Lycoming's design is sitting high in the engine, so any oil that is on it drips down after a while and the cam is sitting exposed naked to the atmosphere.) Once corrosion starts to happen in the cam, the surfaces that are supposed to be very smooth get rough, and it is only a matter of time until it eats itself up. This is why people like engines that have been run frequently, at least 50-100 hours per year. Where in the country the engine has sat also has an effect -- dry Arizona is much better than humid Florida. Also, if the engine has already been through many hours (500+, certainly your 2000) this is less likely to happen than on a new engine: I was told that over time a thin layer of carbonized oil residue forms that protects the metal from corrosion. But of course even this cannot last indefinitely -- things rub against each other and wear out. For example flight schools (which fly their engines a lot, 500-1000 hours per year at least) frequently run their engines 3000 hours, so 1000 hours past TBO, with no ill effects. Another factor here is also that over time all kinds of rubber seals age, hoses can develop cracks, etc. This is another reason why Lycoming says that after 2000 hours *or* 12 years it is time to overhaul. Take what I wrote with a grain of salt, as I said I am not a mechanic and all my understanding comes from reading threads like this and also operating Lycoming engines for around 25 years. Best of luck.

Is this something that is happening because of the way newer cams/lifters have been made more recently? If that is the case, the OP's plane may not have this issue, as the engine is original since 1979.

I have been looking for the same kind of prop to replace my 3-blade McCauley on my 1970 E-model, and so I have quite a bit of information for you. (But I gave up on my search for the reasons below.) 1) You could buy the same prop that you have now, used/overhauled, for about $11k, from a guy in Las Vegas who deals in used props. My guess is it is not a great deal. I can get you his info if you want. Alternatively, you could possibly find for about $4-5k a used prop similar to the one you have, but with an earlier hub (not B-style), which requires periodic (100 hour) eddy current inspections. Probably you don't want this. 2) You could buy a brand new Hartzell Top Prop from @Cody Stallings for somewhere around $12-$15k, you need to check with him. I don't know if you need a new spinner with the new prop, but those can be had used for around $500. Cody is highly recommended by the Mooney community, and at this price it is probably a much better deal than the ones above. Some people complain that the Top Prop has a caution range where it is not recommended to operate the prop between 2350-2550 RPM above 24" MP which they say is a big enough inconvenience. 3) MT makes a nice three blade composite (wood + carbon fiber, I think) propeller that many people say is very nice, but it is quite pricey, probably around $20k my guess (no concrete info). I think the biggest advantage of that prop is that it removes the caution range of the Top Prop, and it is quite smooth from what I understand. 4) Many people do not like the McCauley 3 blade prop that is STCed for the E model (and I suspect also for the C). For this reason you can find quite a few of these used on barnstormers for very reasonable prices ($5-6k), in good condition. I think @Alan Fox for example sells a nice one for $6k, but check compatibility. The main complaint people have is that they say it a) robs you of about 35 lbs of useful load, and that weight is added to the front of the plane, which reduces your cruise speed slightly; and b) it is impossible (or much harder) to balance properly, resulting in higher vibration in the cockpit. a) is definitely true. But for b), I have that prop and had been complaining about vibration, and it turned out it was caused by some slightly loose engine mounts, which when corrected improved things a lot. Also, the prop specialist at Poplar Grove told me that it is very important that the prop be mounted following McCauley's instructions to the letter, and that he sees many such props that are not mounted correctly, contributing to further vibration. He said in his experience he can get these props to be very smooth unless there is something technically wrong with the prop or the engine. I will be going to them in 10 days to have them do their magic and see how that works. I can report back. BTW, you did not tell us why you need a new prop. If you have a good condition used prop with a B-hub but with blades that do not pass overhaul limits, you can probably find somewhere serviceable blades to put in that hub for much less money than the $11k the guy in Las Vegas is asking for. A good B-hub is worth quite a bit of money as well, probably north of $3-4k.