PT20J

If it gets dimmer with the nav lights on, then something is either obstructing the lens or the bulb isn't getting enough current. This would be something amiss inside the annunciator panel. If it doesn't get dimmer when you turn on the nav lights, then there is likely a bad diode inside the annunciator, or a broken gear down return wire between the annunciator panel and the nav light bus, or all nav lights are burned out. Skip

A common feature of full flight simulators nowadays is to be able to depict another aircraft or vehicle on the active runway. Many years ago, I met the NASA researcher responsible for that. She was doing some research using airline pilots in a full motion simulator at Ames Research Center. (I believe she was studying something related to flying instrument approaches but I no longer recall the details). This was back in the 1970s before computer generated scene simulation so the simulator used a terrain board and "flew" a camera down to short final on a scale runway (it couldn't actually complete the landing) with the image depicted on a large projection screen outside the simulator windscreen. She had the cockpit rigged with cameras recording over the shoulder shots of the pilots, scene and instrument panel. One day near the end of the study and just for fun she placed a miniature model airplane in position and holding on the runway. Surprisingly, several pilots were so consumed by the task at hand that they completely ignored the obstructed runway. They didn't recall seeing the holding airplane until they were shown the over the shoulder video and they were pretty shook up about it. So, if experienced pilots can get so focused on a particular task that they don't see an airplane on the runway, they can certainly tune out any lights, buzzers or placards. A friend was sitting in the runup area years ago when he saw a Bonanza about to flare with the gear stowed. He picked up the mic and started yelling for the pilot to go around to no avail. When the plane slid to a stop, he ran over to see if the pilot was OK which he was though shaken. My friend asked if the pilot had heard him calling frantically on the radio and the pilot said he heard something but he couldn't make it out because there was a loud horn going off. Skip

The factory loves duct tape. There is probably a roll or two in each airplane. If you strip out the entire interior as I did recently, you will find they used it to seal all the gaps around the wing roots, baggage compartment, access panels under the rear seat and the baggage compartment, foot wells, etc. The spar huck bolts are also covered in duct tape. There is no reason to remove this tape routinely unless you are inspecting for corrosion. You should not have corrosion if the windows don't leak (especially the pilot's window) and no one spills carbonated drinks in the back seat where it soaks into the carpet against the spar. Skip

A curious thing about the gear down annunciator light is that it is normally grounded through the nav light bulbs, the filaments of these bulbs in parallel having a low resistance to ground when off and the annunciator current being too low to illuminate the nav lights. When the nav lights are on, a diode causes the gear down annunciator to ground through a resistor reducing the current and thus dimming it. I'm curious if anyone has noticed any changes in behavior of the gear down annunciator light after changing to LED nav lights. Skip

I haven't landed at SFO for years, but I don't think Signature is the problem. According to AOPA, Signature charges a $39 ramp fee that they will waive if you buy fuel (which is $8.06/gal). The airport assesses a $232 landing fee - Signature just collects if for them. Last Signature FBO I used was at KSAF last year and they waived ramp fees if I bought fuel which I needed and the self serv fuel was a reasonable price and the personnel were friendly and helpful. Skip

Just ignore the nattering nabobs of negativism.

Parker, I’m curious what the upper limit is where additional hours don’t matter for TT, MM, RG. Skip

https://flywat.com/products/hubba-hubba-cap-gen-2-for-6-aircraft-wheels?gclid=EAIaIQobChMI-M6Z44DN6gIVVh6tBh0UdQEHEAAYASAAEgL7OPD_BwE

Standard tubes need air monthly or more often. I switched to Michelin Airstops and they only need 1 - 2 psi every few months. Skip

Ammeter. Behind circuit breakers.

Just show your AI the service bulletin. He’s supposed to follow processes specified by the manufacturer when available.

I’ve had this problem ever since I purchased the airplane two years ago. The door seal was original and very compressed. I pulled it off and verified that the door was not quite flush at the top before I replaced the seal with the Brown Aircraft T-9088 called out in the IPC. With the new seal, it is worse. I screwed the “bullet” latch at the top of the fuselage out a couple of turns and that improved the latching force, but it’s still not right. Based on the description in the service manual, I wonder if the doors were all hand fitted to shape at the factory. Skip

Don, Mid Continent is an authorized BK shop and repairs their stuff. I've found them very reasonable. Fixed my KAP 150 autopilot controller and bench checked a Garmin nav indicator that turned out to be OK and only charged me return shipping. Regal Air in Everett WA has a fleet of Cessna 172s with KX 155s and they send everything to Bevan Aviation. Display retrofit is expensive, but the radios are still solid and repairable. Skip

I hangar it if there is a risk of hail but leave it outside with my Bruce's cover otherwise when away from home. The cover was purchased by the first owner (it's a '94 J and I'm owner #3). The cover is in great shape -- I don't think it was used much. But the second owner installed a 406 MHz ELT and the antenna wasn't accommodated for by the cover. I contacted Bruce's and they took it back and added a provision for the antenna at no charge. That's pretty good customer service. As a side note, I used to enjoy flying down to Morgan Hill, CA for dinner at the Flying Lady restaurant owned by Irv Perch, Bruce's father, and named for Bruce's mother who was an avid pilot. Irv had quite a collection of old airplanes and cars in a barn and would gladly show you around. Irv's property included an adjoining golf course and Irv had one fairway made long and straight enough to serve as a grass runway. They would use it to fly his Ford Trimotor out to the Watsonville airshow every year. Fun times. Skip

The servo just meters total fuel flow according to air flow and mixture control setting. There is one hose that goes from the servo to the flow divider. The flow divider serves two functions: 1) divide flow evenly to the nozzles, and 2) it contains a valve that closes off fuel to all nozzles to insure a smooth shutdown. If the fuel flow is not the same to all cylinders, the problem has to be either something clogging the internal passages in the divider, clogged or unequal diameter lines to the nozzles, or the nozzles. Unlike the servo, the flow divider can be disassembled in the field for inspection and cleaning. The nozzles contain a restrictor and these are matched sets with the nozzle body and care must be exercised when cleaning to not interchange restrictors between nozzles. Also, don't poke anything in the nozzle bores to clean them as this may affect calibration -- just soak them in Hoppes No. 9. You can tell a lot about the nozzle condition by comparing the spray patterns in addition the the baby bottle test. Don't worry about wearing out the boost pump; as long as it is pumping fuel it can run continuously. See Precision Airmotive RSA manuals attached... Skip 15-338E.pdf 15-812_B.pdf

I'm doing the same to my 1994 M20J and I'm almost done putting it back together. I didn't mess with the overhead vents. Unless they are not working properly, don't mess with them because Mooney glued everything together. Starting somewhere in the mid '80's Mooney began using epoxy primer (off white) on the tubing rather than zinc chromate (green or yellow). Your's looks like it has a combination of both, but it's hard to tell from the picture. Zinc chromate is a hazmat and not nearly so good a corrosion barrier as epoxy. I'd clean up everything and use an epoxy primer. Check the areas behind all the gussets for missed primer from the factory. The plastic panels are ABS and cracks can be patched with fiberglass cloth and ABS glue. Don't put it on too thick or it softens the plastic. They will look like new if you paint them with SEM. I used Phantom White which is a close match for then beige instrument panels used in later models. Skip

I never tried laser engraving. An avionics shop made a bunch of placards for the museum DC-3 using traditional mechanical engraving. They looked great. But then we discovered that the glare makes the legends unreadable under some lighting conditions.

The cabin door on my J has about a 1/4 inch gap at the top when the door is closed but not latched. This makes it take a fair amount of extra force to latch as the clamshell at the top latch has to spring the door top inward before the mechanism goes over center. The service manual says, "NOTE Door contour can be altered slightly to conform with cabin contour, if needed, for proper fit and sealing." Has @M20Doc or anyone else done this? Any tips on how to do it.? The door is pretty stiff. Thanks, Skip

This is a great point. When I purchased my J with a little ole' Lycoming IO-360-A3B6D, the EDM 700 spark plug thermocouple for cyl 3 had been put on cyl 1 apparently by mistake. So, I had two thermocouples on the same cylinder that allowed direct comparison. The spark plug thermocouple consistently read 40 deg C higher than the bayonet thermocouple. When I replaced the engine, I got a new thermocouple for cyl 3 that mounts under the factory thermocouple and I now get readings consistent with the factory gauge and the other cylinders. The spark plug thermocouple was accurate. The temperature is higher at the spark plug boss than at the bayonet thermocouple location. So, cylinder head temperature depends on where you measure it. I think we stress out way too much over CHTs. I remember when everyone was stressed about shock cooling. Don't reduce MP more than 1" per fortnight or whatever. Now, the generation that doesn't remember that stresses over the dreaded RED BOX. Don't do this, don't do that, you'll destroy your engine. I get it. These things are expensive and we don't want harm them. But, I think Mike Busch has it right. Understand how these things work. Develop some conservative SOPs that minimize workload and have fun flying. Now if you want to do something more radical like cruise at 80% power deeply LOP, then you need to be more circumspect. Skip

I agree with Ross. This is a statement often made by the APS folks and it is an over simplification. It arises from the observation that the brake specific fuel consumption curve is very nearly linear for the first 50 deg. F or so LOP. So, you can approximate the percent power if you know the fuel flow which is easily set by the mixture control. The APS formulas that everyone uses for this calculation are also approximations and the compression ratio that enters into the formula is only a proxy for thermal efficiency of different engines. Skip

Agree — mostly. Ground resonance is a hazard with articulated rotor systems having three or more blades. It can occur during start up or with a somewhat hard touchdown which upsets the lead/lag balance of one or more blades causing the CG of the rotor system to go off center and setting up the oscillation. Normally, the dampers in the landing gear will damp out the coupled motion to the airframe and the rotor system rebalances and the oscillation quickly subsides. If one or more of the landing gear dampers is defective, the oscillation can build exponentially with positive feedback between the airframe and the rotor system unless the helicopter is immediately lifted clear of ground contact whereupon the rotor system will rebalance. Skip

Dynamic balancing corrects the prop/spinner combination for a condition where the center of mass is not in line with with the center of rotation. Balancing may or may not produce a discernible improvement in perceived vibration, but it’s still a good idea as it may increase the life of accessories and other components. An extreme example of a dynamically unbalanced propeller is ground resonance in a helicopter. An airplane propeller would not become this unbalanced (unless it lost part of a blade), but it is illustrative of how the propeller vibration transmits to the airframe. Skip

All aircraft have unusable fuel. The fuel pickup in each tank is slightly above the lowest point to avoid picking up contaminants. For the M20K, the TCDS lists unusable fuel as 48.59 lbs. or about 8 gal. Remember that the ‘E’ on the fuel gauge doesn’t mean ‘Enough’. Skip

Same for me. The E uses an IO-360-A1A so dynamic counterweights can’t be an issue. Skip

Definitely a good idea to ground lean as higher combustion temps prevent lead fouling plugs and lead deposits on valve stems. Not sure why you would need to lean for takeoff at low density altitudes. Does it run rough at full rich? What’s your takeoff fuel flow? Most people report between 17 and 18 gph. The IO-360 is pretty tough, but leaning at high power increases CHTs and reduces detonation margin. Skip