Vance Harral

That's probably about right at current prices, but the darn things seem to inflate in cost about $5/disk per year. The first time I ever looked into it (over a decade ago), you could find 'em for about $80 apiece. Next time I looked they were $95, then $100, then $105, etc. We replaced our mains at annual this year and paid about $115 each. Moral of the story: if you think they're getting close, just replace 'em now. They'll probably be more expensive next year.

Factory specifications for shock disk replacement should be documented in the maintenance manual for your airplane. I have a 1998 M20J maintenance manual, and the relevant details are in Section 32-81-00. No jacking is involved. The procedure is to leave the airplane on the ground, fill the tanks, and measure the gap between the retaining collar and the top retaining plate. Basically, you're measuring how much the disks compress with weight on the wheels. The allowable gap is 0.60" for the mains, and 0 (no gap) for the nose. The amount of play after jacking, how long it takes the disks to uncompress, the date code on the disks, etc., are all reasonable things to consider. I don't have any particular beef with mechanics using those factors to recommend replacement. But that's not how the factory spec'd it.

I'm in, link please. Profile says Erie, CO which is where I live, but airplane is actually at KLMO, not KEIK.

As a fellow M20F owner, I'd suggest there's little reason to pay the extra cost and weight penalty for the 35AXC. We've been running the 35A model for over a decade with zero problems. First one lasted 8.5 years and was still "usable" when we replaced it, just starting to show very early signs of reduced total capacity. Bought another which has been running strong for 3.5 years. Aircraft lives in Colorado, near Denver, and sees occasional days above 100 and below 0. We don't use a battery minder or anything similar. We do fly frequently, but the airplane occasionally sits for several weeks, and has always fired right up. Finally, some people report having to modify the top of the battery box to fit a Concorde battery, but we didn't need to do so for the 35A. Based on my experience, the extra cold-cranking capacity of the AXC is irrelevant for an IO-360-AIA engine. The AXC does give you 17% more total capacity, which theoretically gives you 17% more time with electrical power if your alternator gives up the ghost. But the scenarios where that would matter are pretty far into the corner cases.

One way to deal with this sort of thing is to bill a wet rate instead of using a dry lease, based on the cost per gallon at the home airport and typical fuel burn. In this case the company always reimburses for fuel purchases, rather than only when the top-off rule isn't followed. There is a tiny amount of "unfairness" in this due to variations in actual gallons-per-hour used by different operators, but it's trivial. In exchange, administration gets a lot simpler. In particular, it makes it easier to deal with situations like the fuel pump being closed, or the case where operator #1 asks operator #2 to leave the tanks down a bit because the next flight is going to be heavily loaded. The operators already have money going into and coming out of some sort of escroe account to pay the dry rate, so it's really no more overhead to deal with fuel reimbursements at the same time the flight is "billed" - just have everyone clip fuel receipts in the same logbook you use to track tach/hobbes time. We've run our partnership this way for a long time and it's worked well.

Your pointed reply with boldface type nicely illustrates the point I'm trying to make. Saying these pilots are not partners due to their lack of an equity stake makes it clear you don't see them as equals. They're just "renters" to you. No matter how nice and/or experienced they are, if you treat them like renters, they'll treat your airplane like a rental. You need to be OK with that. Some renters are better than others, of course. That judgement call is up to you. To be clear, I get that you're the only one with capital investment, and it's not unreasonable to want more/all of the control because of that. Adults are free to enter into any honest agreement, and I'm not saying your arrangement can't work. I just think it's uncommon for arrangements like this to work well over the long term. People who don't want to pay for an ownership stake usually discover it's better to rent from a business with no emotional investment in the rental machine, even when that comes with per-day rental minimums, etc. I have seen the arrangement you're proposing work out OK when the "renters" are actually aircraft owners themselves, who just want occasional access to a different type of aircraft. Usually it's reciprocal. Any chance your renters are aircraft owners themselves, or at least have been in the past? If so, that probably improves your odds of a good long-term arrangement.

For those of you interested in water ditching strategies, the following is a good read: http://www.equipped.org/ditchingmyths.htm It's the only research I'm aware of where someone actually tried to look at NTSB records and determine what strategies and situations matter. Among other interesting points, the author contends there is no data to suggest ditching with wheels down (or in fixed gear airplane) makes any measurable difference in survivability vs. wheels up. He also says skill, planning, and preparedness for ditching don't seem to matter much either - student pilots with little experience and no knowledge of "recommended" ditching procedures tend to do as well as the Gray Eagle Ace-of-the-Base.

If you really trust your potential partners and believe everything is going to work out, give them equal scheduling rights, and equal say in how the aircraft is operated and maintained. Trust that they'll treat you fairly about scheduling. Ask what they think should be in the operating agreement and incorporate their ideas. If you're unwilling to do these things, I predict a negative outcome. I've been part of a successful partnership for 14 years and I know it can work out well. But I wouldn't enter a partnership where one person wants a greater share of privileges and say-so in aircraft operation because the airplane is more theirs than mine. I understand you're carrying a greater share of the capital investment and responsibility in exchange for it, I just think it's unlikely to pan out when some of the pilots are second-class citizens. Not because it's "unfair", just due to human nature. Ask yourself, if one of your friends dings a wingtip or spills orange juice on the seats, is it no big deal because these things happen and it's just a machine, or are you going to be irritated at their carelessness with "your" airplane? The answer to these questions has a lot more to do with the success or failure of the partnership than the rental agreement. The agreement is important too, but it's secondary to the attitude with which you're going into it.

Sorry you had a bad experience, we've had zero trouble with ours in the 7 years it's been installed. That's just one data point, though. There are certainly opportunities for things to go wrong with it.

I wired ours to the terminals of the sonalert, rather than the stall sensor itself. Saves running a set of wires out into the wing.

Something about that doesn't seem right. Assuming $100/hour labor, that's 50 hours - more than a full week. I try not to cry "inflated mechanics charges!" without understanding details. Was there something complicated about your installation? Other work done in addition to the AV-17, or maybe a bunch of old wiring removed? By way of comparison, I did the wiring myself and had the mechanic inspect it. Total cost, about $350 for the hardware, plus one hour of labor for inspection and sign-off. The work is mostly just adding wires to existing connections via screw-on ring terminals, no soldering involved. It does help to have a firm understanding of electrical behavior, to understand where an AV-1 inverter or equivalent is needed. As an amateur working very slowly, it took me a couple of days to do the wiring. That doesn't include the time to study the Mooney system schematics and fully understand the AV-17 manual, though. I'd like to think a decent shop would already have that knowledge or at least not charge you for their learning curve, but maybe that's debatable. I completely understand that some folks don't enjoy the DIY approach. But even turning the whole process over to the shop, I would have guessed $2K total cost at most.

Probably not the issue, but to scientifically complete the experiment, you'd need to perform stalls at altitude in your normal landing configuration (which you said is usually full flaps, occasionally partial). In your original post, you said the stall warning came on at 70 KIAS in the "no flaps" configuration while airborne. The indicated airspeed at which the stall warning horn will come on with flaps extended is slower. But only by a few knots. I did read where you said you make full-stall landings and agree it's odd you're not hearing the sonalert on landing. Absolutely. One of the best and least expensive upgrades we made is the addition of an EI AV-17 Voice Annunciator to our airplane. In addition to the factory sonalert tone (which I agree is easily missed), we now get a "check airspeed" warning through an always-on feed into the audio panel. It also generates voice alerts for the landing gear warning, engine monitor alarm, low bus voltage, and low vacuum. My mechanic was willing to sign it off as a minor modification.

Made the mistake a few years ago of asking a line service person to add air to the nosewheel right before departure (I no longer air up tires right before departure). On landing a couple of hours later, the nosewheel was flat. Landing was uneventful, I didn't even notice until I was down to 40 knots or so on the ground roll, at which point it began to shimmy. The shimmy became more and more pronounced as I slowed down. By the time I couldn't steer any more, I was fully stopped, and the local FBO sent a tow rig out. They replaced the tire (which was about due anyway) and tube, and I was on my way in less than an hour. My guess is the Schrader valve simply didn't close properly when the line service guy person removed the air hose. I don't think there was any malice or incompetence, just one of those things. Again, I no longer air up tires right before departure any more. I either do it when putting away the airplane in the hangar, or I wait around a while before departure.

Maybe. Such a system requires three microswitches and three lights, which is 6 components that could fail and give false indications. That's at least a 3x greater probability of indicator failure than the current one switch/one light system. That doesn't even take into account the fact the over-center microswitches and wiring to them would necessarily be exposed to the elements in open gear wells, as opposed to being tucked in the belly. That makes them more likely to fail or become mal-adjusted. There's a reason instructors train students transitioning to complex airplanes not to trust the squat switch that's supposed to prevent retracting the gear on the ground. With due respect, I think you're over-weighting an unlikely failure mode in the linkages, and under-weighting the much more likely failure modes of your proposed indicator fix. Think about how many threads we've had here discussing microswitch problems (squat switches, stall warning switches, flap limit switches), vs. the number of threads about failures in the mechanical gear linkages. As for the camera, sure, there's a pathological case where the gear can extend so far as to appear to be down, but just barely not be over center, and you wouldn't see that on the camera. But now you're really at the corner of the corner case, man. The microswitch you propose wouldn't have to be mal-adjusted very much at all, to have the exact same problem of falsely indicating down and locked.

Not sure I'd recommend leaving it on all the time, but the advertised continuous battery life is 2 years, i.e. even longer than the recommended calibration period. I can tell you mine has now been accidentally left on for several days on two different occasions (pilots in the partnership forgetting to turn it off). It's still running on the original battery, so it's pretty clear battery life is measured in weeks/months rather than days. Even if the battery does wear out, it's not like replacements are expensive or difficult to obtain. A two-pack of CR123A batteries is $6.72 on Amazon: https://www.amazon.com/gp/product/B01B3EQR8A/ref=oh_aui_detailpage_o06_s01?ie=UTF8&psc=1

If you're serious, this seems pretty straightforward. Search NTSB records for Mooney gear-up landings, subtract out the ones where a per-wheel indicator wouldn't help you (e.g. collapsed after rollout, forgot to put the switch down, etc.). Everything left *might* be a failure of the type you describe. My guess is that number is very tiny, but I haven't researched it myself. Based on having inspected and handled the pushrods in question, it seems like it would take a tremendous amount of force to bend one in the manner seen in your photo above. How did that happen? It seems almost inconceivable to me that an electric gear actuator could do that (circuit breaker would pop first). If that's from a manual-gear airplane, it would seem someone with major muscles (or major motivation) must have really leaned into it. All that said, if this is really a concern for you, may I suggest installing a live streaming camera - e.g. a Garmin VIRB. The FAA has essentially capitulated on such things being "portable" devices that require no special approval to install. Clamp one on your tail tie-down such that it can see all three wheels. When you put the gear down, just take a look at the live streaming picture on your tablet or phone to confirm.

Yes, but only if there's been a major mechanical malfunction, such as the bent pushrod discussed above. The whole system consists of a series of interconnected pushrods. The switches and lights track the position of one of those pushrods, while the floor indicator tracks another. You can see exactly which pushrods are monitored by looking in your parts manual and/or at your airplane next time you have the belly panels off. But nothing tracks the "final" pushrods attached to the gear trusses and/or the over-center links, hence Mooneymite's concern

I guess my question is to what extent Mooneys have suffered more, or more injurious/fatal accidents as a result of this "flaw" in the indicator system, vs. GA retractables with per-wheel indicators? We have 50+ years of data on this, what does it say? You're certainly correct that there are failure modes which are not caught by the current indicator system. But it's not clear a different system would save more lives or dollars. Don't forget that a more complex indicating system would have more complex indicator failures, potentially leading to bad outcomes that would not have happened with the simpler system. In my 25+ year career in engineering, I can't tell you how many times I've seen systems that were (re)designed to catch some corner-case failure, actually wind up causing more trouble than the original corner case. My gut instinct is that when each wheel is an independent system (e.g. hydraulic), independent indicators are a good solution. With the mechanical linkages in our Mooneys, the combination of an electric (switches) and mechanical (floor line) indicator seem quite adequate.

Agreed, those are the jump planes and they do enter the pattern from steep descents. On the other hand, I've never personally had a "crazy skydive pilot" scare in 15 years of flying at Longmont. I find the current batch of jump pilots to be professional. They pay attention to what's going on in the pattern as soon as they roll in after the drop, position appropriately on the way down, make reasonable radio calls, and work into a reasonable spot, slowing down if necessary to do so. No dive bombing in front of everyone, as seems to be the stereotypical complaint about skydive ops. This is not to say I've never heard a single complaint about the jump planes. But to be honest, the complaints I recall tended to come from pilots who I felt lacked some experience and understanding of different speeds and energy management. A King Air entering mid-field downwind at 150 knots is not "cutting in front of you" if you just turned crosswind to downwind at 75 knots in a 172.

As a local, I'm inclined to say this sounds like a bigger deal than it really is in practice. The jump aircraft inform Denver TRACON when they're about to drop, and also make an announcement on the KLMO CTAF. So if you're actually going to Longmont, you'll hear about jump activity one way or the other. The only thing you need to do differently is not enter the pattern by flying directly over midfield into the downwind leg (use a 45-to-downwind or enter on base or crosswind). Once you're in the pattern, you just fly a normal pattern, even with jump activity. The jumpers come down south of the runway, with plenty of clearance from the runway itself, as well as the downwind leg. In my opinion, the biggest risk from jump activity around Longmont is to transient aircraft trying to squeeze between the mountains and the western edge of the Bravo without talking to anyone. Pilots unfamiliar with the area might use KLMO as a landmark and fly right over the top without being aware of jump activity.

Well, it goes up to 12K. Agree an Ovation can easily top that, but I wouldn't necessarily recommend flying over the top of the bravo as a routing strategy. It would be a heck of a slam dunk from the west edge to any of the local airports. 12,500' also puts you right around the altitude of the highest peaks to the west, and hence in the worst turbulence from the very common westerly winds. Instead, I'd advise taking advantage of IFR services or VFR flight following from Denver TRACON and just going through the bravo. I know a TBM driver who gripes about the routing they give him coming into Denver because he's up playing with the jets. But they've always treated me well down at piston altitudes. Not sure what altitude the OP likes to cruise at, but the most reasonable rides on summer afternoons here are going to be either below 9000', or way high, like 18K and above. The latter isn't really practical in an unpressurized aircraft. The direct route from Chattanooga does go right over KDEN, and ATC is unlikely to clear you on that route (though they'll occasionally let you go right over the top of the runways). But a minor deviation to the north (say, via the AKO VOR) is likely to get you cleared through the north side of the bravo at a reasonable altitude, whether VFR or IFR. Lots of options out that way too, if you need to wait out a line of afternoon T-storms and complete the trip after dark. KAKO is an obvious choice, but don't count out KFMM in Fort Morgan. It's a small airport and a small town, but they have a courtesy car you can take into town for dinner, and you can get the keys after hours even when the airport is unattended.

Robert, when you finalize your trip details, feel free to PM me. Our airplane is based at KLMO, and I live just a couple of miles from KEIK. Always happy to help out a fellow Mooney pilot with a ride or whatever. With sufficient notice, I can probably loan you a car for a couple of days if you like. My advice is to not necessarily get fixated on a particular airport. KBDU in Boulder itself is a decent airport in good weather. But KBJC, KEIK, and KLMO are all very reasonable driving distance to Boulder (about 20 minutes), so you have a wide variety of choices for approaches, runways, etc. All these airports have maintenance facilities and self-service fuel at reasonable prices. All have transient parking. There may be overnight charges at KBJC, I'm not sure about that, but you can always call and ask. I can vouch for the folks at Fly Elite Aviation in Longmont. They'll take care of your airplane, minimal/no fees to park on the ramp, and they have competent mechanics who are Mooney savvy on the off chance you have a maintenance issue (we have all our maintenance and annuals done there). If you're more comfortable with towered airports, KBJC is towered and has upscale FBOs with nice lounges, TVs, etc. As for KBDU, while it is indeed closer to the mountains and lacks approaches, the truth is it's rare to "need" an instrument approach around here. The weather tends to either be good VFR, or unflyable IMC due to icing or thunderstorms. Concur with the advice of others that things are statistically easier if you arrive in the morning, having holed up in Kansas or eastern Colorado the night before. But it's also completely reasonable to delay your decision of a specific airport until you're an hour out or so, then just take whichever of KBDU/KBJC/KEIK/KLMO seems best suited for the weather conditions. If you need or want to make a local flight for pleasure or to re-position your airplane, I'm available as an "advisory" CFI. No charge for fellow Mooney drivers.

Mooney by moonlight, just this week.

A respectfully dissenting opinion: We bought our 1976 F model with an inop Brittain B-5 system, and eventually restored it to fully operational condition. The downsides are that it took a lot of time and energy to do so, and the end result doesn't perform nearly as well as a modern digital autopilot. The upside is that our total investment - and I mean total investment over the last 10+ years for everything from overhauled servo boots, to flaky rotary switches, to IRAN'd valves, remote compass unit, etc - is well under $2K. This for a 3-axis autopilot that holds altitude, tracks headings, courses, performs approach intercepts (lateral only, no vertical), and works well with the GI-106 indicator driven by our GTN-650. Brittain can even set you up with GPSS if you like, though we haven't gone that route. It's not a great autopilot compared with modern options, and I wouldn't recommend taking on the job of fixing one unless you're a techie type who really enjoys reading the old manuals and doing a lot of owner-assisted maintenance with the help of a friendly A&P. But the support from Brittain has been great, and the value for the dollar is absolutely unbeatable.

Thanks, guys. I'm aware of the accident history, but hopeful it was repaired instead of scrapped. I may try e-mailing Ridgeaire.