EricJ

You can still see the cross-hatching through those streaks, so they don't appear to be very deep at all. If your compression is good and the valves look good I'd leave it until the next inspection and see if it is gone or gotten worse.

You can look in the Illustrated Parts Catalog (IPC) for your airplane to find the original part that went in there. I replaced mine a few years ago and the Radio Shack speaker that was original was no longer available. I substituted a speaker that fit with similar impedance. IMHO it falls under the "standard parts" category, so you can use what fits and substitutes for the original. I'm not aware of any FAA-PMA speaker sources. I don't think Radio Shack was ever FAA-PMA.

Thanks, but I already deleted the vacuum system and replaced the AI with a G5, so I committed to not fixing it quite a while ago. Several others took a crack at it and it got nowhere, and that was after spending an unexpected (and unauthorized) five figures on overhauling the whole thing a year before it quit. It was just a bad idea to spend any more money on it.

I have two friends who are just starting commercial aviation careers and building time. One is flying right seat in King Airs flying doctors around, and the other is flying Caravans for a tour/charter operation. They're both enjoying what they're doing, and both building turbine time pretty quickly and getting paid for it. One is on an established path to an airline, and the other is just sorting out what he wants to do which is most likely not airline. I was in a conversation with one of them and a guy who flies for NetJets, which sounded pretty interesting and accessible as well. It looks like there are maybe a few more interesting paths these days than in the past.

High mechanical stress (centrifugal force, plus force the blades are producing), plus tight tolerances. The tolerances are tight to prevent leakage around the outer perimeter of the blade disks, and those tolerances have to be maintained under stretch due to centrifugal force, heat cycles, etc., etc. The hot sections have crazy mechanical and thermal requirements, so none of it is easy to make or inexpensive. Even as an A&P if I were maintaining one myself, a hot section inspection could get very expensive just due to parts costs alone, and you can't skimp or you'll regret it. And the costs are high even on the non-rotating parts, like fuel and oil systems, etc., etc. They just cost a lot, and they're expected to work reliably for many heat cycles over many thousands of hours, so the engineering is difficult but if it is a working airplane or otherwise flies a lot, the costs are distributed over a long time, presumably with the associated reliability benefits.

I just did mine as well, including removing and cleaning out a few zerks. Some of the joints are just difficult.

AGMs in automobiles tend to do that...just suddenly quit. In AZ it's usually associated with either the first hot weather in the spring or the first cold weather in the fall. Maybe it's just what AGM technology does. I did have some warning, but not much time from functional to sketchy.

That was what killed my Century III as well. The AI had to be overhauled, and after reinstallation the autopilot never worked right, except in my case the problem was roll. The worst part was that it worked fine on the ground. All the ground tests worked, and I even took the AI out of the panel and if you moved it by hand the controls would respond correctly, but in the air it was essentially dangerous. I even bought a second AI but it behaved the same. I've been hand-flying ever since, which has been more than five years now.

Nice. And that bulletin is fourteen years old. So we're full circle from don't bother, to must test it every year, to mostly leave it alone. This does, however, encourage people sharing their capacity test result histories, since that's the recommended basis for determining when to test. After my recent experience I think my schedule will be to test at five years and go from there. I'm also backing off how often I connect the minder. I just finished an inspection cycle today and left it unconnected...oh, my!

That's a good input point.

Yes, the solid side goes toward the rotating surface, i.e., the plug.

Looks orange for chrome cylinders.

Was that cylinder removed or worked on recently? I'm not seeing the case crack. Bummer in any case. Best of luck with outcomes. Glad you got it on the ground okay.

FWIW, the City of Phoenix only allows two things to be continuously plugged-in in a hangar: a fridge at least 18" above the ground, and an approved battery minder. Only some Schauer and BatteryMinder models are approved, including the one for the Concordes. Since they pass the city lawyer paranoia risk test, you're probably fine. They do require the interface kit with the Anderson connectors, too, though.

The Concorde reps come to our local IA seminars and give talks every year, and they have some very good reasons why a minder is a good idea, and they recommend using one. This is why I use one, plus it's always nice knowing the battery is essentially topped off whenever you go to use it. It mostly has to do with the way AGM batteries are constructed and behave, and their batteries in particular. One of the main benefits is the desulfating cycles in the minder that keep the plates clean, which is a primary reason for battery failure. The rehab process in the CMM is intended specifially to attempt to desulfate the plates, so if they're kept clean by a minder in the first place, the expectation is that the battery life is extended by the minder. They do only recommend the minder listed specifically for their batteries, since apparently the desulfating and maintenance cycles are best for how their batteris are constructed. https://www.aircraftspruce.com/catalog/elpages/batteryminder_11-19239.php For pertinent details I'd recommend attending an IA seminar where the Concorde reps give a session. IA seminars are usually free and open to pilots and owners as well, usually with Wings credit. Concorde actually sponsors on-line webinar IA renewal seminars, and there's one in January: https://www.concordebattery.com/training/ia-renewal-2025.html Our local IA seminar is usually blessed with sessions by both Concorde and Gill, and I often attend both.

Unless there's a hermetic seal between the cap and the rest of the EIS, pressurizing the cap will pressurize the rest of it, too. That said, the cap where the distributor is is the only place that pressurizing should matter on an EIS. Depending on how any vacuum advance works that could be affected as well, though.

The TCDS is again the authoritative reference, since the IO-360-A3B6 engine is only approved for the M20J. That McCauley prop is listed in the TCDS for the M20J, but not for the M20E, probably since it has a different engine. The TCDS does not list that McCauley prop for an M20E, in fact it only indicates two models of Hartzell propeller. Anything else would require an STC or a field approval. BTW, the TCDS for the Mooney M20 is 2A3. I think Rev 58 may be the latest.

Yes, the load capacity test is pretty straightforward. The constant-current discharge rate and ending voltage are programmable.

I had an interesting development lately. I've been capacity testing my Concorde RG-35AXC battery every year or so, and it's been consistently hitting 95-100% capacity testing both during a capacity test and verified during a recharge cycle with my Topdon charger, which also measures capacity during the recharge. But the battery performance has still been dropping during that time, as measured by slower cranks, and deeper voltage sags during starter operation. I did some engine work a couple weeks ago, and when I went to start it after reassembly it did a quarter turn and stopped. Erk. On a second try it turned enough to start, and I figured I'd try a local flight and see what it did. It started for that as well, but then during a hot start at the fuel pump after returning it was definitely starting to turn a lot slower just before the engine started. So I got a new replacement, which is now back to spinning the prop like crazy with the skytec, and thought I'd check the old battery to see how it's doing. Open circuit voltage on the old battery was still great, 12.8V when I took it out of the airplane, which showed as 12.9V with a different multimeter before I started the capacity test after bringing it home. I got a Kunkin tester to replace my old semi-homebrew unit which could ony test at half current, so this test went more quickly. The result was 27.13Ah capacity, or 27.13/33 = 82% capacity. When the Topdon recharged it, it reported a 28.1Ah capacity, which is still only 85% capacity, which is Concorde's recommended threshold for removal from service. OCV after the recharge was 13.3V. Since it was already having trouble I didn't think it was worth attempting a rehab cycle, especially since I already had a replacement. If replacements weren't available a rehab attempt would have definitely been an option. The battery is nearly six years old, and has lived in Phoenix its entire life and we're not yet through a brutally hot summer with long strings of contiguous record-breaking high temps, so it may have just been enough to push it over the edge. The more remarkable thing to me is how quickly it went from testing 95+% capacity to notably tired and questionably servicable. The last capacity test was in March and tested at 34.2Ah, which was confirmed during the recharge by the Topdon at 35Ah (both a little over 100%). The summer was either hard on it or it was just done, but the change from testing 100% to out-of-service in about six months suggests that other tests, like the voltage sag during start or just observation of starting behavior, may be a more reliable indication of a failing battery. The capacity test seemed to not provide adequate warning under these particular circumstances. Anyway, just thought I'd pass that along. A successful capacity test may not be a reliable indicator of the ability of the battery to make it another year.

There's not a pack that I'm aware of for the interior hardware that holds things like the plastic panels, etc., together, but you can get all that at the aviation aisle of Ace Hardware or similar places. At least, that's where I get mine.

I think you're okay without them, but check the POH/AFM for your specific aircraft in the Limitations section in the Kinds of Operation Equipment List. I have an example M20J POH that appears to be in the 96-ish timefreame, and they're not listed there. If they're not on there, you're good without them for all kinds of operation. In the Equipment List in the POH/AFM I have they're listed but with negligible weight and arm, so removing/replacing them doesn't affect WnB, either.

They're good on mine as well, and the pucks are far from new. However, we had to use a pipe through the knuckle and floor jack to raise a C model wing high enough to get it up to change a flat tire. Then we could get the 24" Alpha jack under the wing and lift it further for sufficient clearance with the new tire. So if a tire is flat it may not fit.

I'm just noticing that the pic of my 149-NL is while it was still on the TIO-540, so it is not representative of existing clearance on my airplane.

Oh, that's not encouraging. :'(

The stock Prestolite is a ginormous boat anchor compared to the 149-NL. An EC would have to be similarly huge to create a problem. Whatever he has in the pics, it doesn't look that big. Edit: BTW, my 149-NL was removed from a TIO-540 that had been installed on a Malibu, which is apparently why it has a Lycoming part number sticker on it.