Vance Harral

I ordered a tube of Aeroshell #7 from Aircraft Spruce at the beginning of September, and I'm still waiting on the order to be filled. I need it for our annual in April, and I'm starting to think I need to look elsewhere.

A neuron fired, and I remembered the one other thing I wanted to contribute to this thread. The IPC specs ordinary AN hardware for the landing gear side brace bolts; but AD 78-15-02 requires following the instructions in SB M20-212 to replace those with NAS 1306 high strength bolts, see https://www.mooney.com/wp-content/uploads/2020/12/SBM20-212.pdf. If you're ordering new hardware for these bolts, order the NAS 1306 hardware, not the AN hardware spec'd in the IPC. If you order your hardware from LASAR, they'll likely send the correct hardware. If you're just ordering from Aircraft Spruce based on the IPC, you can wind up accidentally un-doing an AD.

I went through a similar exercise a few years ago. You might find this thread I posted at the time helpful:

Out of curiosity, can you guys elaborate on what undesirable behavior occurs in a GFC500 installation without the yaw damper? I haven't flown or ridden in a Mooney with a GFC500 autopilot. But the local flight school I teach at (amazingly) has GFC500s in every one of their airplanes. So I've flow with them in 172s, 182s, and a PA-28, including on 1 or 2-ish hour XC flights. Some of these airplanes lack the pitch trim servo, and manually managing trim is mildly annoying. But none of them have the yaw damper servo, and I can't detect anything about the way the airplane flies that I think would be improved with a yaw-sensing gyro, including flying in turbulence. My opinion is uninformed, however, having never actually flown with a GFC500 yaw damper in any airplane at all. I'd like to learn more.

For a professional look, I can strongly recommend engravers.net. Lots of choices, but I recommend black 0.020 Lexan with silver text. Matches vintage-era placards very nicely, plastic rather than metal as PT20J suggests. What I really like about the engravers.net guys is that they'll custom cut the placard to any shape you want, drill holes, etc. You just have to give them a detailed template. I send them a to-scale PDF with dimensions, and I get back exactly what I spec. Very inexpensive, too.

Caution is appropriate, and a thorough pre-buy is always a good idea. But lack of ADS-B in 2022 is arguably less likely to be indicative of a poor maintenance attitude than other "deferrals". A number of aircraft owners simply don't want to be tracked, don't fly in rule airspace, and therefore don't need or want ADS-B. I'm not one of them, but I know some. I think those of us who like ADS-B and/or live in big metro areas, tend to forget there are still huge swaths of airspace where ADS-B isn't required even after the 2020 deadline. In general, it's not required in Class E airspace outside the lateral boundaries of Class B/C, up to 10K MSL. Quite a lot of country falls in that category. Not sure where the OP is buying his airplane, but if it's based out of, say, some small town in the midwest, the lack of ADS-B doesn't necessarily mean the current owner doesn't care for the airplane.

Cowl flaps should be operated based on observed cylinder head temperature. It's not an "always open during this phase of flight, and always closed during that phase" thing. Your normally-aspirated Lycoming is generally fine at any cylinder head temperature between 250-400 degrees. Below 250 is too cool for the lead scavenging agent in the fuel to activate, and you're likely to get plug fouling. Above 400 starts to affect engine longevity. Halfway between those points is 325. Consider that a soft target (don't agonize over it), and open/close cowl flaps as needed to stay around the target. On a hot summer day, cowl flaps will need to stay open during the entire climb. After leveling off for cruise, it may take quite a while for CHTs to cool down below 350 or so. Don't close the cowl flaps before that happens. On a cold winter day, I still have the cowl flaps open for takeoff (checklist item and force of habit), but if I look at CHTs early in the climb and see them under 300, I'll close the cowl flaps while still climbing. I'm not always perfect at executing this strategy, and neither is anyone else. Fortunately, it's not an especially critical item, at least not in 4-cylinder Mooney models.

I think what you're really asking here is, "what's normal"? The replies to this are going to be model specific, because different models of Mooneys had different elevator pitch control systems: some have bungees, some have a counterweight, etc. Concentrate on replies specifically from other F model owners. In our 1976 M20F, the spring bungees incorporated into the pitch control system result in a stiff elevator feel, even when everything is properly assembled and lubricated. With the trim set to the takeoff position, I would estimate it takes nearly 20 lbs of pressure to hold the yoke either fully back or fully forward against the stops. That's the effect of the bungees. When I fly the airplane with two passengers in the front seat, and set the trim indicator about 1/2 inch further up than the marked takeoff setting (a very reasonable choice with no weight in the back seats), I wind up pulling about 10 lbs of force on the control wheel to get the nosewheel to unstick. Once the nose comes up, I relax that pressure, and the airplane climbs nicely at that trim setting. So if you're experiencing around 10lbs of force from time to time, I'd call that normal. If you're experiencing 20/30/more lbs of force, something is wrong.

Just a data point for the OP: I've known Brian Pickerell for about 20 years, and the seller of this aircraft for about 3 years (he's an enthusiastic aviationist, has gone from zero hours to CFII in that period, and has over 400 hours in this particular Mooney). Both of them are personable, standup guys. That doesn't mean either/both of them might not have missed something, and you should still get an intensive PPI on any airplane you buy. But I promise you're not deliberately getting a lemon unloaded on you by shady characters.

Your best bet is to discuss this with Bruce Chien, as others have indicated. You don't need to join another message board to do so, and in fact that's not really the best approach anyway, as he gets so many questions that his answers on those venues are understandably clipped. Suggest you contact him directly via http://www.aeromedicaldoc.com/ and offer to pay for an hour of his time as a consultant.

Paul's airplane is at KBJC, and he's not (yet) an instructor. I'd like to help, but I'm not really the right guy for this. I've got about 30 hours' dual given in the right seat of K models, but only giving instrument instruction, flight reviews, etc. to pilots who have already received transition training and have plenty of turbo Mooney time. My airplane is NA, and as much as I understand the principles of turbo engine management, I wouldn't trust transition training to any instructor who doesn't have significant left-seat turbo time.

The runway at KBDU is 4100' in good condition. Field elevation is about 5300'. Margins start to get a little thin in something like an Ovation at gross weight, but A/B/C/E/G/F/J models are fine, provided winds aren't squirrely... ... and that's really the only reason I don't recommend KBDU to newcomers. The wind can be funny there, being right in the shadow of the flatirons. Much of the time, winds are light out of the east at the surface, and there's nothing to hit off the end of runway 8, so risk factor is low. When the prevailing west wind kicks up enough to push to the surface, those unfamiliar will choose 26, which points right at the mountains. The issue isn't actually the mountains themselves, it's that the topography around there can generate a wicked downdraft just a bit west of the runway. The tow pilots I know there won't take off on 26 unless the particulars of the day and airplane they're flying will allow them to turn crosswind at or prior to the end of the pavement.

Another vote for KBJC instead of KAPA. Speaking as a local, I'd urge you to also consider uncontrolled options (KEIK, KLMO), but you won't get 24-hour FBO staffing there. Signature is the "established" FBO, at KBJC, but I've heard good things about new-kid-on-the-block Sheltair. No personal experience there, though. Note that KBJC has a self serve pump which is competitively priced with nearby uncontrolled airports. But any savings is probably eaten up by what the FBO will charge you if you don't purchase fuel. FBO fees and policies change frequently depending on who's working the desk, phases of the moon, etc. Strongly suggest you call a day or two before arrival and figure out which of Signature or Sheltair is offering the best deals for piston singles.

What airport and flight school/flying club?

@TheStig moved to Florida. But there are other Mooneyspacers in the area, including myself (M20F) at KLMO and @gsxrpilot (M20K) at KBJC. My airplane is the last year of the M20F. It's effectively an early-model M20J in the cockpit (electric gear and flaps, 6-pack panel, etc.), it just doesn't have the airframe speed mods that make the early model Js 10-15 knots faster. If you can't find an actual M20J to ride in, my airplane is a decent facsimile. I'm tied up through the end of the year, but would be happy to give you a ride shortly after the New Year if someone else doesn't before then. For the M20M, you probably do want to find a ride in a long-body model, and I don't have any inroads for you there. Hopefully someone else will step up and offer a ride.

Fair question, and one of the things we checked when deciding to install. With the balls on the yoke and the compass up on the center post, the distance is large enough not to have any effect. No, I didn't do a full before/after compass swing. But before attaching, I moved the ball mounts from "far" away, up to the yokes, wiggled them around in the yoke area, and didn't see any visible movement of the wet compass. This is not an acid test, but no worse in practice than avionics shops which never re-swing the wet compass after installing new gizmos, even though it's technically required. Data point: I have a magnet of similar strength on my key ring, and I put the keys on the glare shield during preflight, which tends to wiggle the compass. I worry a (very) little bit about buggering the compass that way, but I confess I just do it anyway. That key ring magnet needs to be within about 12" of the wet compass to actually produce any visible movement. If I put it on the far edge of the glare shield, the field strength just isn't big enough to matter to the compass. Makes you appreciate how strong the "weak" magnetic field of the earth really is.

Not until just now!

That's a Nite-Ize "Steelie Ball" mount for phones/tablets. https://www.amazon.com/Nite-Ize-Original-Steelie-Magnetic/dp/B01JJP5JAW/. Note that this link is to the larger, more expensive size, designed for tablets. Don't confuse it with the smaller, less expensive size, designed for phones only. We have one of these mounts on each yoke in our airplane. It's far and away the best phone/tablet yoke mount I've found, for a couple of reasons. First, there's nothing faster than a magnetic mount for attach/de-attach. Just pop the device on/off the yoke in a half second. No clamps, no tabs to click in, etc; just on and off, immediately. Second, a ball mount allows you to swivel your phone/tablet around on the yoke. Very handy if you want to switch from portrait to landscape orientation, or just make a slight adjustment when the sun happens to hit an angle that causes glare and/or a blinding reflection.

That sounds about right to me. Labor adds to the $700 kit cost if you're not your own A & P, but swapping injectors is not a labor-intensive job. Maybe a couple hours worst case (sometimes you need to go multiple rounds of swapping with GAMI to get the absolute best result). Call it $1000 all-in, and a 200 hour payback worst case. This is a theoretical argument that assumes one meticulously manages the mixture at all times. If you're a little lazier like most of us, and/or spend a lot of time flying around the pattern, doing IFR training, etc., you're not going to save the full 0.8gph during every hour of operation. Regardless of those quibbles, though, there is always going to be a break even point within a few years. Up to each pilot to decide if that's the best use of their dollars compared with additional training or other alternatives. Let's try not to confuse the original poster, who has a normally aspirated engine (as do I). Turbocharged Senecas and 252s have the option to run LOP in cruise while still maintaining "rated" cruise power (60%, 65%, 70%, 75%, whatever - take your pick based on desired engine longevity). One can simply push the throttle forward, increase manifold pressure, and maintain rated power up to the critical altitude of the turbo. That ability to maintain rated cruise power and run LOP without slowing down is attractive. If I had the privilege of operating a turbo'd bird, I'd likely fly LOP in cruise. At optimum cruise altitudes in a normally aspirated engine, however, it's a tougher sell. Running LOP and also making rated cruise power requires staying low, where additional drag is working against you. Climb up to optimum NA density altitudes of around 8K and you're likely below max rated cruise power even at the best power mixture. Going LOP there slows you down. Still a great tool in the tool bag for increasing range when needed. But a lot of us normally-aspirated drivers just can't stand to give up the knots it costs to get the benefit, even though that's an emotional argument that has little impact on real-world, door-to-door enroute times.

If we're going to get into details, let's get it exactly correct. Balanced fuel flows across all cylinders increase engine smoothness at stoichiometric mixtures, and mixtures lean of stoichiometric. Producing the same amount of power under these conditions requires injecting the same amount of fuel, because fuel is the governing input to the combustion equation. Unequal amounts of fuel -> unequal amounts of power developed -> engine roughness. But unbalanced fuel flows across all cylinders in rich-of-peak operations have (almost) no effect on power developed, and therefore no effect on engine smoothness. The reason is that the excess fuel in a rich mixture is simply unused, and blows out the exhaust unburned. It doesn't matter whether you have "a little" more fuel than the stoichiometric ratio, or "a lot" more. The power developed is the same (well, aside from the effects of small differences in additional cooling, and the density of the material exiting the exhaust system, which explains the less-than-flat power/mixture graph on the rich side). If your point is that unbalanced fuel flows across cylinders can allow some cylinders to be ROP while others are LOP, sure, that's true. But that is not "best power", which is the point you are emphasizing: Best power in an aircraft cylinder is always rich of peak (100-200 degrees ROP for the typical Lycoming, see graph below). If the mixture crosses over into lean-of-peak operation, the cylinder is not running at best power. Furthermore, as the graph shows power decreases more quickly on the LOP side than on the ROP side. So in an engine with less than perfectly matched fuel flows, best power is achieved when one cylinder is around 150 degrees ROP, and all other cylinders are still ROP. Again, if any cylinder actually crosses into LOP operation - where fuel flow does affect the power developed - that is by definition not best power. LOP operations tend to produce plug that look nice when pulled for inspection and gapping. But let's be careful with the word "fouling", and distinguish cosmetics from actual mis-firing of the plug. As a primarily ROP-in-cruise flyer, I have zero problems with misbehaving spark plugs. This is almost certainly because I aggressively lean during low power ground operations, which is where essentially all plug-fouling-of-the-type-that-causes-misfire occurs. Barring very extreme cold weather operations, any power setting actually used in flight produces sufficient cylinder combustion chamber temperatures for the lead scavaging agents in the fuel to do their trick, and it's generally lead contamination that causes poor spark. Again, the plugs from a primarily-LOP-flown engine will tend to have just a hint of light brown residue on the plugs, while a primarily-ROP-flown engine will have a heavier, blacker residue. So LOP is "cleaner" for the plugs, no argument there. But not cleaner in a sense that actually matters. I'm not finding huge balls of lead down in the plug well when I pull my plugs for inspection and gapping, and I don't have problems with mis-firing plugs. Concur, no argument. If I had GAMI injectors, then instead of flying with one cylinder at 150-ish ROP and some of the other cylinders even richer, all the cylinders would operate right at 150-ish ROP at the best power setting. There would be no difference in the power developed or the speed I traveled at vs. without GAMIs, but fuel flow would be a few tenths of a GPH less.

Some additional info: the basic reason for wanting closely matched fuel flow from each injector is to allow the engine to run smoothly when all cylinders are operating lean-of-peak (LOP). If you want to operate in this regime, (more efficient, cleaner, but always slower in a normally-aspirated airplane), then you *might* want GAMI injectors. If you don't care about operating LOP (value speed over efficiency, don't have problems with plug fouling, etc), there is little reason to invest in them. As a data point, the famous "GAMI spread" in my IO-360-A1A is not particularly good - about 1.0 GPH difference in fuel flow between the points across which the four cylinders hit peak EGT. But I'm still able to operate with the last cylinder to peak running at 10-20 degrees LOP. The engine runs a little rough at that setting. Not "OMG it sounds like it's going to quit" rough, just a little fatiguing. I don't particularly care about that, because I rarely choose to run LOP. Therefore, I'm not especially interested in GAMI injectors. If I had problems with plug fouling, was more concerned about CO poisoning, or just really enjoyed the efficiency vs. speed tradeoff, I'd run LOP and likely invest in GAMI injectors.

Cleaning the engine to bone dry is indeed the first step. Once that's done, I've had good luck with UV leak detection dye, e.g. https://www.amazon.com/Interdynamics-Certified-Fuel-Systems-Ounce/dp/B002M4G24U, a trick explained to me by a long-certified A&P mechanic. Get everything bone dry, pour a bottle of the dye into the oil fill tube (don't spill it outside the engine!), run the engine at high power for a short period of time on the ground, de-cowl, and use a cheap UV flashlight in a dark hangar to look for the source of leaks. I know of no specific regulatory prohibition on doing this, but I make no claim that it's legal/approved/etc. The most conservative approach is to do this coincident with an oil change. Add the dye right before the change, ground run the engine (to warm it up for the oil change, natch), identify your leaks, then drain the oil-with-dye as part of a normal oil change before you fly again. There is no particular reason to fly with dye in the oil anyway, as airflow through the cowl at speed just tends to blow leaking oil away from the original source of the leak anyway. For what it's worth, we did this after the conventional steps of replacing the rocker cover gaskets, tightening up the couplings on the cylinder head drain-back tubes, etc. What we found was a small leak at one of the pushrod tube seals that we had fixed, and a series of small leaks around the oil pan gasket, which we have chosen to live with in the short term (dropping the oil pan to install a new gasket is somewhat major surgery).

Thanks guys. Sounds like the over-center mechanism isn't actually going over center when the knob is all the way forward. I'm hoping the fix is as simple as adjusting the cable in such a way as to find a sweet spot between the over-center mechanism engaging as designed, but not getting false ram air warnings.

Thanks for the replies so far. These are Slick 4347/4370 mags, sounds like no lock washer. These are overhaul/exchange mags, installed 4/26/2019 when the prior slick mags failed inspection. They have about 250 hours of service to date. They were timed at the annual about 8 months and 80 hours ago, by the shop A&P; but I don't know if they were actually "touched" at all then (I wasn't there, sometimes the timing checks fine and no adjustments are necessary). So no very recent maintenance, and I don't have any particular reason to believe the screws were installed incorrectly last time they were touched. Perhaps this is just one of those things to check every time the cowl is off.

My airplane partner graciously performed an oil change today, and called to say that when he removed the oil filter, he found a machine screw sitting on the "shelf" directly under the filter. On further investigation, he traced it to the ignition wire cover plate for the left mag, as shown in the attached photos. Neither of us are A&Ps, and we're not sure of the implications of this. My partner re-installed the screw, used his general mechanical experience to torque it to what he felt was "about right", and performed a post-oil-change run-up and mag check with no issues. But we're between A&Ps at the moment (our on-field shop recently closed), so I'm asking the collective wisdom of Mooneyspace for further guidance. The screw in question doesn't have any kind of lock nut that we can tell. Seems like it's secured only by friction, which is a little creepy. Other than checking all the other screws on both mags, anything else we should do before flying again? Any guess what might have caused it to back out? This is the first time we've had a problem like this in 17 years of ownership, so I have no prior experience.