PT20J

The thin plastic with the foam core was probably BA-189-139. It is softer than the T-9088. But the problem with it is that the foam deteriorates over time and the seal loses its resiliency. Brown Aircraft discontinued it (I called them) and Mooney switched to the T-9088. The T-9088 works but the positioning is critical. The bottom is the hardest to get right because there are no latches or pins to hold the door tightly closed, the door hold-open arm is located on the bottom edge, and the curvature of the door frame corners does not match the curvature of the door. I had to remove the right seat and lay inside with the door closed and use a flashlight and a Sharpie to mark the proper location for the seal on the bottom. Along the top and sides, the centerline of the bulb should be placed on the line of rivets fastening the inner and outer door panels together. EDIT: A trick Don Maxwell uses if there is still an area (usually along the bottom) where the seal isn't tight enough even though it is positioned properly is to cut off a piece of the flat "tail" from a left over piece and glue that under the door seal to shim it a bit. I had to use that in one spot and it worked great.

The breather tube on my M20J is stiff and I asked Frank Crawford what it was made of and he looked it up and the drawing says poly vinyl. It would seem that Tygon might be a better choice on the older airplanes as well.

I've tried it. I had a discussion long ago with aeronautical engineer and handling qualities consultant Roger Hoh who pointed out that not all airplanes wind up tighter and tighter and faster and faster until making a smoking hole in the ground. Spiral divergence is caused by the directional stability being greater than than the lateral stability. But the longitudinal stability can be a factor also. Normally a Mooney phughoid lasts about 2-1/2 cycles. If you get the airspeed right (trimmed to about maneuvering speed) and the airplane is well rigged, I've let a spiral start power off and watched it stabilize in about a 45-degree bank and get almost to redline before the nose started up and then it got almost to stall before the nose came back down and then did this another time and a half with lower amplitude each time until it finally stabilized at trim speed in a 45 degree descending turn. This was long ago in my 1978 M20J. I haven't tried it in my 94 J.

It took me a few tries to learn how to do this. The placement of the seal on the door is critical. The gap between the door and the fuselage is not uniform. If you use the proper 3M yellow adhesive, there is an hour or so open time to reposition the seal. Don't use too much adhesive -- a thin coat on both surfaces is all you need and be sure to clean the seal and door with denatured alcohol first. After positioning, I close the door on a sheet of printer paper. If the seal is positioned correctly, the door will latch but take some pressure to close and the paper cannot be pulled out without tearing. If it won't shut or the paper is loose you can reposition the seal. If you use the Brown T-9088 seal and shut the door and leave it for a couple of days it will take a set and the door will be much easier to close thereafter and it won't leak.

M20C checklist.pdf

The up limit switch is in a fixed bracket and the adjustment is on the little paddle on the push pull tube, so I didn't have to worry about the adjustment.

The truss and spindle should last darn near forever if properly lubricated at regular intervals. The leg wears on the bottom plate where the weight of the airplane rests on it. The later horns are hollow and should be filled with grease. I suspect that a lot are under lubricated. I don't see why a steering horn can not be rebuilt in the field.

The power to the gear motor in the up direction runs through NC contacts in that switch. When the gear reaches the end of it's upward travel, the tab on the retraction rod activates the switch which breaks the circuit and stops the motor. Similarly, if the gear won't lower, it could be a problem with the gear down limit switch.

I'll bet any good machine shop could rebuild one of these. It's not complicated.

It should be clear if you look at the schematic for your serial number whether it’s wired this way or whether there is a fault.

According to the GFC 500 STC, the red button should be labeled AP DISC/TRIM INT or AP DISC. It looks like the CWS legend next to the black button in your picture has worn off or been painted over.

Looks to me like they just made a flat plate to go over the top of the B-K base. The PTT is still on the front. The GFC 500 doesn’t use the CWS button. Looks pretty straightforward.

Both.

The Cygnet CA3112-G switch used by Garmin can be made to fit in the B-K base. Someone else posted this picture of his installation:

It's a readily available Micro Switch DT-2R-A7. TTI, Inc had the best price - $113.47.

The landing gear failed to retract on my 1994 M20J. I removed the belly panel and exercised the up limit switch several times and thereafter it worked again. The switch comprises two components: A micro switch and a plunger. The plunger is spring loaded and I noticed that it was a little sluggish to reset when I removed it so I cleaned it and lubed it with some silicone spray. The problem may have been mechanical or there may have been a problem with the switch, but I replaced the switch anyway.

I just want to be clear: I am not commenting in any way on @OHAEDO's unfortunate circumstances. He suffered an expensive loss and chose a particular course of action for which he explained his motivation. It didn't work out in his favor and he has publicly accepted the fact and moved on. What interests me is to understand if there is a towing damage failure mode singularly unlike all the other failures that have been reported over the years.

Not sure which part you mean. But some time ago LASAR quit making many of the PMA parts. Corrine Boatright told me that they had been made by a machinist in Lakeport that had retired and they hadn't been selling enough to warrant enlisting a new machine shop. I exchanged emails with the new owner and he claimed that they were able to rebuild landing gear actuators and nose gear legs in Prineville, but when I later inquired with Dan Riesland about having a gear leg repaired he told me that they could not do it because they needed to get new FAA approval since they had moved to a new FSDO jurisdiction. Corrine and Dan are gone. It's probably best to call LASAR directly for current status.

I might get a stethoscope and listed to the actuator. You could also move around underneath and listen to various components while it’s moving.

I'm still stuck on what broke and how it was due to towing if it didn't break the stops or dent the tubes. If something sheared up higher I wonder if whatever broke was defective. New airplane. Maybe a hairline crack in a weld let loose after a few landings. When I ordered a replacement gear leg from Mooney a year ago I had to reject the first one due to pinholes in welds that were leaking oil from inside the tubes. Were there ever any pictures of the damage posted? I don't recall seeing any, but may have missed them.

No. And don’t for details. It’s all explained above if you care to read it.

I'd contact Frank Crawford at Mooney. I don't know if the 40:1 gears were a Mooney produced part or a Dukes part. But if they were a Mooney part, Frank might be willing to look up the specs. He may not be able to share a complete proprietary drawing, but If he can email you the material and any heat treating, you could use that as approved data for a one off OPP.

Agree with Jake. The ILS Energize input on B-K autopilots enables the GS.

The problem with quantifying battery life is twofold. First, what defines end of life: Failure to pass capacity test, of failure to crank? The former will occur long before the latter. Second, is how the battery was treated. What temperatures was it stored at? How many times has it been run completely down and how long did it sit discharged. Has it been used for a lot of short flights where it may not get fully recharged? Is it kept on a battery minder? Concorde's FAQ says typical life is 3-5 years.

He was absolutely correct in this statement. However, he should have also pointed out that there is a lot of WRONG information from maintainers. That's why we have to verify what anyone tells us. Good for you to delve into this.