Vance Harral

The 40:1 gears were installed as OEM equipment in later-model Mooneys with additional lower doors on the landing gear, and higher Vle/Vlo speeds. I presume they came from ITT, which was the manufacturer of the actuator at the time. They are not a "retrofit" in the sense of being special, one-off parts, manufactured specifically to address SB 190B. Rather, a case of using parts from a newer design in an older housing.

Every few years, someone posts a question like this about the electric gear actuators and the related AD/SB. Whether intended or not, I feel like it often has an air of, "The gears don't really wear out, right? The AD is just a scam?" But that's fine, nothing wrong with being skeptical and asking real owners what they've actually seen. Every time the question is asked, though, I feel obligated to relay my anecdotal experience that yes, the gears really do wear out. Specifically, in 2009, at ~2200 TT on our 1976 M20F, the 20:1 gears were worn to the point they failed the 1/2-tooth backlash test. They had a scalloped shape, just like the SB/AD shows. This happened despite dutifully servicing the actuator as required, during the 5 years we owned the airplane after purchasing it in 2004. But we couldn't tell from the logs how often - if ever - the actuator was serviced prior to 2004. It's possible the prior owners neglected to maintain them properly, and they wore out sooner than they otherwise would have. But I'm also reasonably sure those 20:1 gears were original equipment from 1976. Regardless of how they were maintained, I consider 33 years to be a pretty reasonable lifetime, and I was not upset about the replacement cost. We installed 40:1 gears in 2009 (they were readily available then) and have serviced the actuator every other annual since. In practice this works out to about 150 hour servicing intervals, which seems very reasonable. The 100-hour "part 2" action in SB-190B is not possible with our particular actuator, as it has no grease fitting. In fact, our actuator is actually an ITT LA11C2114 rather than the LA11C2110 called out in the SB. So technically, neither the AD nor the SB applies to our particular aircraft. But we act as if it did, per advice from Don Maxwell. I have always performed the gear inspection myself, with a mechanic looking over my shoulder. So I have lots of personal data points on what our gears look like over time. Here in 2024, 15 years and another 1300 hours since the 2009 swap, I am definitely seeing a small amount of wear in our 40:1 gear set vs. what they looked like new. The wear is almost undetectable from inspection to inspection, but cumulatively over time, even the 40:1 gears are developing a slight amount of scalloping. I don't lose any sleep over this, and it's likely I'll be long retired from aviating before this set of gears fails the backlash measurement. But I attest the wear is present, and something worth paying attention to - same as other long-term maintenance concern like exhaust, landing gear biscuits, engine overhaul, etc. I freely concede that one data point from one owner isn't necessarily applicable to other airplanes. But I disagree with the premise that properly-maintained gears last "indefinitely". I've seen the wear over time with my own eyes.

I sympathize, this would seem weird to anyone who has an understandably simplistic idea of battery capacity. But it's useful to understand there's really no direct way for a G5 or cellphone or any other battery-powered device to determine how much charge remains in the battery; so this idea of "percent charged" is something of a lie. Modern battery-powered devices use computer algorithms based on empirical tests to estimate time/percent remaining, and those algorithms get less accurate as the battery ages. Every such algorithm has weird corner cases that the designer desperately tries to avoid exposing to the end user, but sometimes they creep through. Weird discontinuities are one aspect of that. Another is the huge variability in how much longer a battery lasts once it's down to the "red zone" (10%, or whatever). For some excruciating detail on this, you can start with https://batteryuniversity.com/article/bu-903-how-to-measure-state-of-charge. Full on nerds like myself can go on to look at individual ICs that implement certain charge counting algorithms, e.g. https://www.analog.com/en/products/max17263.html

This is entirely reasonable advice. But "early" is subjective, and as you note, wind at the surface is often lower than wind at altitude - even 100' AGL can make a significant difference. I don't necessarily want to encourage pilots to wait until the landing flare to establish a crosswind slip. But I've also coached a few pilots on the more timid side, that inability to hold the extended centerline in a slip when they're hundreds of feet above and a half mile from the runway threshhold isn't particularly meaningful, and they might be giving up on things a little early. The reasonable abort altitude varies with skill and experience, of course. I think it's a good exercise to go up to a safe altitude and practice getting into and out of slips until one's comfort with doing so increases. The purpose of this isn't necessarily just for crosswind landings. Smoothly adding and removing slip on approach is also a nice drag management technique for precision landings, particularly in simpler airplanes with fewer drag configuration options.

You don't really need to have a new faceplate fabricated to "reorient" that vertical layout. The folks at engravers.net will make you a thin overlay in metal or lexan that will stick on top of the existing plate, based on a dimensioned drawing you send. All you'd have to do is remove the switchplate nuts and turn knob, stick on the overlay, then reinstall. I've used engravers.net several times for new/updated placards. They're inexpensive, and look great - every bit as good as factory original.

The mistake you made is common. I've experienced it dozens of times, mostly teaching new student pilots to do a mag check. I do try to avoid it, and I'm not saying it's no big deal. But it's also very likely that nothing was damaged. Certainly take a look - maybe at the next oil change - but I wouldn't lie awake at night worrying about damage to the airplane or to your ego.

I know the "Normal Procedures" section of many POHs prescribe full throttle when leaning for best power in a normally aspirated airplane at high density altitudes. But let's apply some sanity here... Go ahead and perform that full-throttle leaning operation at high DA, once, which won't hurt your engine as others have noted. Then make a finger smudge mark or use a grease pencil or a post-it note or count turns or whatever, to mark where the mixture knob wound up. Then immediately repeat the leaning procedure, but use a lower "run-up RPM" instead of full throttle: 2000 or 1700 or whatever. Note the difference in mixture position between the two methods. For the vast majority of normally-aspirated GA airplanes, the difference will be small to non-existent. Then go look at a power-developed-vs-mixture chart, maybe like this one. Observe that it's very important to not run full rich at high DA, because developed power drops off significantly; but observe also that once you've leaned anywhere near best power, the curve is very flat. This means small differences in mixture setting around the best power point make very little difference in developed power. Certainly not significant enough to be the difference in whether you hit that tree off the end of the runway. So even if the mixture setting you get at 1700 is slightly different than what you got at full throttle, it doesn't matter. If these observations hold true for you and your airplane, it's rational to conclude you're not giving up anything meaningful by leaning for best power at less than full throttle. It's also rational to conclude you don't need to take minutes-on-end to carefully dial that mixture vernier to eek out the last 10 RPM of indication. Just set the mixture at or near full rich, quickly bring the engine to runup RPM; adjust the mixture in a timely manner for a decent RPM increase (doesn't take more than a few seconds), and get on with your mag and prop checks. Doing so saves prop wear, paint nicks, gas, and noise complaints from the neighbors, with no compromise in safety. This approach is appropriate for the vast majority of the piston GA fleet. To be clear, there are some exceptions involving pressure carburetors and other interesting mixture animals. But for your basic 172 or Cherokee or non-turbo Mooney, there's just no convincing evidence that it's important to use full throttle when leaning for best power at high DA.

I know this isn't the answer you want to hear, but I don't think the orientation matters in practice. The IPC illustration for the main gear doesn't display the bevel on the collar. The IPC illustration of the nose gear may show the bevel, but it's not clear, and doesn't seem to match where the bevel actually is (see attachment). The service manual doesn't mention the bevel, it just refers to installing "the collar". And as you note, the retrofit kit doesn't mention the bevel either. I just looked through some old photos I took of measuring the gap with respect to shock disk replacement, and I can see the bevel in the photos on one side of the mains (bevel up) and I can't see it in the photos of the other side (bevel down, or not there at all). I can't see any obstruction that the bevel would clear, nor can I see any reason the collar would be easier to remove or re-install based on the orientation of the bevel. The only thing I can think of is that perhaps the bevel is designed to snug against the bolt head. But I have a sneaking suspicion the beveled collar was actually designed for some application, and just happened to be convenient for use in our airplanes.

Can you post a picture of your panel, and let us know what engine monitor you are considering?

Maybe relevant:

It tells you nothing? On the contrary, it tells you a heck of a lot. This idea that asking prices are completely divorced from the reality of sales prices only has merit when N is small. It's a fair point if you're talking about the single Hawker Sea Fury for sale on Controller; but not for, say, an M20J. The dozens for sale on Controller/TAP/whatever have a price range that is almost perfectly linear with engine time, and it's extremely unlikely anyone is selling an equivalently aged model for half the price advertised on those sites. The reason is that some very healthy percentage of people advertising airplanes and RVs and other toys actually want to sell them, and will move asking prices as needed to do so. Sure, you get the occasional weird outlier ("Of course the airplane is for sale, honey!"), and that's why the asking price for that Sea Fury isn't meaningful. But I'll say it again: Mooneys are not special exotics. There are enough of them on the market that asking prices on the for-sale sites are a fine way to estimate current values. That's the only place Vref and similar tools can get data anyway, so it's not like those tools have some special edge that individuals don't. Even brokers who give you valuation advice are not going to disclose exact sales prices to anyone other than the buyer and seller of a particular transaction, because doing so would kill their business. None of this is to say that an extremely casual buyer can't occasionally be successful with a lowball offer, or that an extremely casual seller can't wait years until a sucker comes along. But for people who are actually serious about buying or selling a Mooney in a timely manner, everything you need is on the for sale sites. That'll be true until the inventory gets so scarce that there aren't enough data points for the market to be rational.

If we're going to be good nerds about 1.2 or 1.3 times Vs0, remember that this rule of thumb is based on calibrated airspeed, not indicated airspeed. In the average Mooney, indicated vs. calibrated airspeed error in the landing configuration are pretty close, so it doesn't make a lot of difference. It's more interesting to have this conversation about other airplanes, particularly the venerable Cessna 172. Vs0 at gross weight in a 1978 172N is 41 KIAS. But if you look at the airspeed calibration tables, 41 KIAS in the landing configuration is 48 KCAS, a difference of almost 20 percent. 48 * 1.3 gives you a rule-of-thumb approach speed of 62 KCAS, which converts back to 60 KIAS, per the airspeed calibration table. That's smack dab in the middle of the 55-65 KIAS speed recommended for a normal landing in the 172N POH. If you don't understand that, you might instead compute 41 * 1.3 = 53 KIAS, and either claim the 172 POH was written by a bunch of lawyers who added unnecessary fudge factor for liability reasons, or that the 1.3x rule is bogus. But that would be bad analysis. You can certainly make a nice, short-field landing in a 172 at 53 KIAS approach speed; but there's not much stall margin left at that speed if you're really at gross weight.

While Jimmy's guide is helpful (though not sure when it was last updated), and Vref was nominally interesting, I've never really understood these "What's it worth?", and "How do I value it?" questions... at least not for common airplanes in the modern era of everything being advertised online. At the risk of coming off as a jerk, they seem lazy. Anyone thinking about dropping 6-ish figures on an airplane shouldn't be daunted by reading ads and typing some stuff into a spreadsheet. As I write this, there are 99 Mooneys listed for sale on controller.com: 9 Acclaims, 17 Ovations, 1 Eagle, 10 Bravos, 1 L model, 22 K models, 25 J models, 7 F models, 2 E models, 4 C models, and 1 B. Plenty of data to understand ballpark market value. Pick your model of interest, narrow a bit by engine time or avionics or whatever; drop the highest and lowest, average the remaining ones, subtract 10% or so to differentiate asking vs. selling price, and you've got a general answer. That general answer doesn't necessarily apply to a specific airplane you might make an offer on, but Vref wouldn't do that for you either. Indeed, I suspect at least part of the reason AOPA is dropping Vref is that fewer and fewer people need or care about it. If you don't like Controller.com, look at Trade-a-plane, Aerotrader, etc. Heck, just go look at Jimmy's inventory directly: https://www.gmaxamericanaircraft.com/inventory/?/listings/for-sale/aircraft/13?dscompanyid=6946&dlr=1&settingscrmid=614667. It's not like aircraft prices are some closely guarded secret you can only find through dedicated valuation services.

Everyone's family is different, but consider the possibility that by the time the kids are heavy enough to make a significant dent in useful load, they won't necessarily want to go on flying trips with you. Not because they don't like you or don't like flying, but just because such is the nature of teenagers. Several of us speak from experience on this front.

Thanks for the point-out, @Marc_B. PM sent to @BageMooney

I have no doubt most shops can overhaul the gyro part of a Brittain TC. Less sure about the shuttle valves and associated roll trim mechanism inside that device, though my guess is it's not complicated machinery. Our Brittain TC requires nearly full right roll trim for the wings to actually stay level, and we've contemplated "doing something" about that for a long time. We've verified rigging (airplane stays wings level in in still air with balanced fuel tanks and PC disabled), and we've also verified good vacuum hold on both the "left" and "right" tubing systems that connect to the TC, via a test rig. So the off-center problem has got to be in the TC itself. Haven't done anything about it because it's not really a serious issue. But the TC hasn't been out of the panel in at least 30 years (per notes from prior owner) and nothing lasts forever. Good to know there is, at least at the moment, a specialty shop that deals in these things.

That used to be an actual requirement, not just something that "could" happen. But in major metropolitan areas, there's so much training traffic in the patterns that it's almost never reasonable to bomb into the key point from a steep spiral that starts way above the pattern; and I'm betting that's one reason it got taken out of the PTS/ACS. I'm sure some examiners ask for it in places where traffic permits. But around these parts, it's effectively off the table - steep spirals and emergency descents are done in the practice area, and power-off 180s are done from a normal downwind, even on the practical test.

Lazy Eights are another maneuver that's weakly specified in the ACS, mostly to accommodate airplanes of varying performance. Because there is no requirement to enter the maneuver at any particular speed, or gain any particular altitude at the highest point, or use any particular bank angle at the apex (ACS just says "approximately" 30 degrees), you can meet the standard with very little pitch and/or bank. A poster on another board once called this variant of the maneuver "Comatose Eights". The argument is that the comatose variant is easiest to fly. But it takes forever, isn't much fun, and I frankly find it hard to teach them that way because the pilot usually cannot get the airplane to continuously change pitch and roll when the total pitch and roll delta is small. What I'd call an "aerobatic" lazy 8 is max speed on entry, whatever pitch gets you near stall speed at the apex, and the max bank angle you're willing to tolerate (in the extreme, it's a 90-degree wingover). That would legally require parachutes, require an actual aerobatic airplane in practice, and probably earn a bust from the examiner even if you were legal due to being grossly in excess of "approximately" 30 degrees at the apex. I think they're easiest to teach in a typical piston single with about 40 degrees of bank at the apex, and that seems to satisfy the examiners around here. Note that if you're doing it right (and being evaluated correctly), nobody is looking at the attitude indicator during the maneuver - you judge "approximately 30 degrees" at the apex by looking outside. The bottom line is that despite the intent of the ACS to take subjective judgement out of the examiner's hands, there is always going to be some degree of interpretation, and this interpretation is most prevalent in the commercial performance maneuvers. Fortunately, most examiners seem to be reasonable about this, and only bust people on things that are clearly stated in the ACS as standards. For the lazy 8s, that's having an exit energy at the 180 point which is within 100' and 10 knots of the entry energy; and - the thing my students tend to have trouble with - continuously changing bank and pitch throughout the maneuver. I spend most of my coaching time pointing out that the pilot has become "stuck" on a fixed pitch and/or bank angle at some point in the maneuver.

Not sure when you did your ride, but the current Commercial Pilot ACS covers this on page A-20, which Marc pasted above. The 2002 version of the PTS has the same selection language, so examiners have had the discretion to evaluate only some of the performance maneuvers for at least 20 years. They are allowed to require all of them, though, maybe that's what your examiner preferred. In practice, it doesn't matter, because you have to be prepared to perform any of the maneuvers. You're not supposed to get advance notice on which ones the examiner has selected for their Plan of Action, and again, they're allowed to require all of them. I suppose every candidate hopes the examiner will only pick their favorites, but at least around here, no examiner ever tips their hand in advance.

One other tip based on the most common mistake my students make. When starting the maneuver - which you will do around 4500' AGL - the geometry is such that the point you are about to spiral around will be almost directly underneath you, and you cannot see it (not even in a high-wing airplane, but especially not in a low wing). If you can see the point you intend to spiral around off your wing as you're about to begin the maneuver, you are much too far away from it laterally. Because of this, I teach students to use a 4-way intersection of some small country roads that extend into the distance, as the point to spiral around. Establish a course over the top of one of the roads while still well away from the intersection. As you come up on the intersection, you'll lose sight of it, but you can use the perpendicular road extending into the distance to know when you're over the top. Roll in to a 45 degree bank at that point. You may still not be able to see the actual intersection at first, but you'll know where it is by the crossroads extending into the distance. As you descend, the actual point will eventually appear off the wingtip.

As others have said, the Commercial Pilot Steep Spiral is a separate maneuver from the Emergency Descent. Don't confuse the two. The Steep Spiral is the commercial maneuver that irritates me the most as an instructor, because the ACS actually provides almost nothing in the way of guidance about how it is supposed to be flown. There is also nothing particularly "steep" about it - the ACS standards do not require any minimum bank or pitch, so you can theoretically perform the maneuver at very shallow angles of each. The only salient point in the commercial pilot ACS about this supposedly "steep" spiral, is that you must complete 3 turns before reaching 1500' AGL. Using optimum turn radius angles of about 45 degrees typically results in a descent of about 800' per turn, and when I start practicing these with new commercial pilot students the first time, they often lose 1000' or more per turn. So you've got to start the maneuver around 4500' AGL. The shallower the bank you use below ~45 degrees, the more altitude you'll lose per turn, and that's really the only thing that forces the turn to be "steep". Again, you could theoretically perform the maneuver with 10 degrees of bank, but you'd need to climb really high to complete 3 turns prior to reaching 1500' AGL. Up here in mile-high country, we have to climb to about 9000' MSL to start the maneuver, which takes a while in a normally-aspirated airplane (even a Mooney). To give us a fighting chance to complete 3 turns by 6500' MSL, I teach the maneuver in the clean configuration, and using minimum sink airspeed, which is slower than best glide. Note that neither the ACS nor the Airplane Flying Handbook actually say to use best glide speed, the ACS says "a specified speed", and the AFH says "gliding speed". I'm not interested in best glide speed because we're not trying to go anywhere, we're staying put over a specific point. And since we have a goal to minimize our altitude loss per turn (again, need to complete 3 turns by 1500' AGL), min sink sink speed is a better way to do that than best glide.

Historically Avemco is a lot more expensive than other carries when you have a lot of experience, but a lot less expensive when you don't. Over the 20 years of our partnership, we have periodically cycled in new, low-time pilots with little/no complex time and/or no instrument rating. In almost every case, we switched to Avemco for a year or two, then back to a traditional broker after the new guy gained more experience.

Availability of overhaul/exchange fuel pumps has been an issue for some time now, I'm not surprised the OP is having problems. We went through this about a year ago with similar results: no overhaul/exchange units to be found anywhere. After a couple of days looking, we gave up and shipped our own unit to Aeromotors for overhaul, and they were able to turn it around relatively quickly. I think the airplane was down a total of less than two weeks. Not a big deal to us, but our airplane is just a hobby toy, we don't use it for business.

The mechanic first tried to drill out the screw, and when that didn't work he simply wrenched the yoke off the shaft, which of course left a big score in the shaft that had to be addressed. No one was there to stop him from ham-fisting it (we don't use that mechanic any more). It was a nightmare, and a perfect example of the unintended consequences of a "mandatory" inspection with thin justification. In a word, no. The yoke shaft type against which the AD was issued doesn't have the set screw at all. It has a roll pin instead, and is a smaller diameter shaft. It's literally not the same thing. Unfortunately for those of us with late-model M20Fs that have the newer yokes and yoke shafts, AD 77-17-04 doesn't exempt our airplanes from the yoke shaft inspection, even though we don't have the parts on which the problem was observed. Those of us who follow the letter of the law are unquestionably performing unnecessary inspections. Those who don't perform the unnecessary inspections aren't following the letter of the law, and may get hassled by future IAs and/or buyers. Pick your poison.

Do you have "late model" rams horn yokes? on your airplane? If so, you're not going to find what you're looking for in the M20F IPC, you have to look in the M20J IPC. The set screw is documented in section 27-30-00, it's an AN565-D416-H4. We applied a very light fingertip "dab" on one side of the threads, similar to what one does with anti-seize when installing spark plugs. It's entirely possible that you used less of the stuff than we did, and that you'll have no trouble later on. But when you start getting into a debate about fractional differences in the amount of thread locker you apply being the difference between damaging a yoke shaft on the next removal, I'd argue it's not worth it. The set screw is not a structural item, and the yoke isn't going to come off the shaft if the set screw is loose and allows some slop. It's just annoying if you're trying to do something like hand-fly a smooth set of lazy 8s.