PT20J

I’ve heard that. The one I got is supposed to glue to the door. It has a V cross section rather than being hollow.

Byron, Are you sure that's the correct seal? According to Brown's website, it's made from 60 durometer neoprene. My M20J IPC calls for BA-189-139 (which I cannot find on Brown's website) or an alternate T-9088 which is sponge neoprene. I'm interested because I need to replace my cabin door seal as well. I bought a Knots 2U seal but I'm not sure I like the cross section. Maybe someone that's used that one can chime in with their experience. Skip

Concrete has great compression strength. It's what your hangar floor is made of

It doesn't really matter if you are only jacking one wheel because the wood is in compression and the other two wheels prevent there being a side load (Same reason TV towers don't fall down - main load is compression and the guy wires prevent a side load). I would not use the bottle jack method to jack more than one wheel at a time though because the base of the jack is too small to provide a high level of stability (no matter how you stack the wood) if there can be any sway. Skip

Yes, but the gear doors are in the way if you place it outboard and the jack is in way of removing the wheel if you place it inboard. That’s why for jacking the main I remove the screw from the jack piston and jack using the Mooney jack points. Placing the jack on a couple of concrete blocks makes a very stable base for jacking the mains. Skip

It's in the instructions for continued airworthiness to be done annually, but this isn't mandatory for part 91.

When I need to jack the whole airplane, I take it to my mechanic's hanger and use his aircraft jacks and engine hoist. But, often I just need to jack one wheel. Recently, I had the need to raise the nose wheel. I had a local fabricator make the tool shown for about forty bucks. It's a ten inch length of 1 inch diameter solid bar stock welded to a short piece of one inch ID pipe. Works great. The same bottle jack works for raising one wheel. I just remove the adjustable screw/pad and the hole in the top of the piston mates nicely with the conical Mooney jack points. (The screw/pad is usually bunged up so that it doesn't come out when fully extended. I clamped the piston in a vice with rubber jaws and worked the screw out, Then I cleaned up the threads on the end. Now I can screw it in or out of the piston easily). Skip

The Precise Flight ICA calls for lubricating the gears annually. I couldn't find any indication that mine had been lubed since they were sent to the factory for overhaul by the previous owner seven years ago. The ICA calls for removal to lube, but that's not really necessary. I found that by removing the bottom plate I could inspect the worm and worm gear. They were dry. I was able to access the sector of the gear that needed lube by raising the speed brakes and applying Aeroshell 22 to the gears with a long Q-tip. The design is such that the gears are exposed to water coming in from the top of the wing which can wash out the grease. If the airplane is left outside in the rain at all, an annual lube is a good idea. Skip 541SMAN0001D.pdf

Since you can’t move it to someplace that can work on it, it might be worthwhile to do some further investigation if you are able. From the description, it is almost certainly electrical and probably not the airspeed switch. If you don’t have the Service Manual and schematics, call Mooney and ask for the pdf files. If you trace out the wiring on the schematic, you will see that it is pretty simple electrically - some microswitches, relays, switches and connectors. You can check all the connections and components individually. Don’t just wiggle them though. Part the connectors and check the conditions of crimps and pins. Some report good success applying Stabilant 22 to the contacts before reassembly. If you can borrow jacks, you can test the gear as you go along. Intermittent problems are challenging. Unless they see something obvious or reproducible, LASAR will just go through this same process. I’d also call a few MSCs and ask for ideas. Don Maxwell, Mark Rouch at Top Gun as well as LASAR have all been generous helping troubleshoot. Kerry McIntyre at KNR has also been helpful. These folks may be able to point you to the most likely problem component based on their experience. Good luck. Skip

If you remove the screw extension from the piston of a small bottle jack, the piston fits nicely over a Mooney jack point. A few blocks of wood will raise the jack high enough to raise a main wheel.

Spruce gets $1035 for a Cleveland nose wheel assy. That's without tire and tube. But these are tube-type tires so the leak is in the tube unless you ran the tire down through the cords or flat spotted it. All you really need is a tube patch kit. But then, you still need to jack it up somehow and carry all the right tools. What cause the punctures?

Price aircraft wheels (and factor in that the mains and nose wheels are different) and think about how often you get a flat (I’ve had one in 40 years when a student locked up the brakes on a Saratoga during a checkout trying to impress me with how short he could land) and you might decide it’s not worth it. Skip

Seems to fall in the category of “if it ain’t broke, don’t fix it”

If you were not a CA resident, there would be no CA tax liability buying in CA and immediately relocating to your home state. As a CA resident you have a limited number of very narrowly defined exemptions. Which one are you using?

For airplanes purchased in TX or CA (I have done both) you pay sales or use tax to the state where you reside and base the plane, not the state where it was purchased (unless they happen to be the same). I was a resident of CA and bought a used airplane in CA for use in CA and paid use tax in CA. I am now a resident of WA, I purchased a used airplane in TX for use in WA and was thus exempt from TX tax (nonresident exemption) but did pay use tax in WA. It would have been the same deal had I purchased the airplane in CA - i.e., no CA tax, but tax due in WA. For CA, from https://www.cdtfa.ca.gov/formspubs/pub61.pdf AIRCRAFT AND COMPONENT PARTS SALES: COMMON CARRIERS, FOREIGN GOVERNMENTS, NONRESIDENTS—Sales of aircraft to common carriers, to foreign governments for use outside California, and to nonresidents of this state who make no use of the aircraft in this state except to remove it, are exempt from tax. Only usage during the first twelve months is considered to determine if the transaction qualifies for exemption as a sale to a common carrier. In addition, the sale and use of property becoming a component part of such aircraft as a result of the maintenance, repair, over- haul, or improvement of that aircraft in compliance with Federal Aviation Administration requirements, and any charges made for the labor and services rendered with respect to that maintenance, repair, overhaul, or improvement are exempt from tax. (SECTION 6366) Skip

The attached service instruction, M20-109, calls for torquing the the bolt every 100 hours. I couldn't find a log entry indicating that this had ever been done on my '94 J, so I decided to do it at the recent annual inspection. We found that the nose gear would bind slightly even at the low end of the downward revised torque. The bolt and bushing appear to be fine. Everything was working well before we messed with it and I don't like the way it steers now, so I'm thinking I'll back the castle nut off one flat. I'm curious if anyone else has experienced similar issues. Skip SIM20-109.pdf

Nice pictures! That's the spring inside the cartridge that pulls in one direction. There is an external spring that pulls in the other. The springs bias the elevator as the empennage moves with the trim. Without the bungees, the trim system would have to change the incidence of the tail by a greater amount to get the same trim effect. This system was used up through the J. Skip

There should be two short bushings on the crankshaft flange 180-deg apart. When you install the ring gear, make sure the bushing hole in the ring gear stamped with an "O" mark is assembled at the bushing identified with an "O" mark so that the timing marks will line up correctly. The prop can mount in one of two positions 180-deg from each other. It really doesn't matter since everything should be statically balanced. See Lycoming SI 1098P. Also, the Lycoming IO-360 series Parts Catalog can be downloaded from the Lycoming website. Skip SI1098P Propeller Flange Bushing Location.pdf

The bungees incorporate springs in both directions, so there is always tension applied to the trim system. The play is usually in the rod ends. All the Mooney controls have some lost motion - there are a lot of rod ends. Dirt is abrasive and wears rod ends out. It’s a good idea to clean them and spray with Tri-Flow occasionally per the service manual. Tri-Flow is a dry film teflon lubricant. Don’t use oil or grease - it attracts more dirt. Skip

In most airplanes, it makes sense on a go around to get the airplane set up in the initial climb configuration as quickly as possible. Usually, the flaps move quicker than the gear, so the landing flaps come off first and then the gear comes up. It’s just more efficient that way. Another reason for this order is that larger, heavier airplanes will continue down hill for a bit even as go around power is added and pitch adjusted for climb and you don’t want to raise the gear until you are sure you are not going to contact the runway. In the DC-3 for instance a go around initiated much below 200 feet will frequently result in a touch and go. In a light twin at low altitude, and beginning the go around from DA or greater, it doesn’t really matter. But for a go around from 50’ at high density altitude, flaps first might be a better idea. Skip

I claim no great expertise in fasteners. My point is simply that fasteners are an engineered component and there is more complexity there than one might think. If a particular set of hardware is specified, it's safest to assume that some engineer specified it that way for a reason. A properly torqued fastener shouldn't come loose in a vibration-free environment. The value of the locking device is vibration resistance and, as the documents and video show, different locking devices have different resistance to vibration. Skip

Well, if it makes you feel better I've heard that PAL nuts aren't really very effective, but I don't have any data. However, I ran across this interesting link and it says a jam nut is more effective if it goes on first. https://engineerdog.com/2015/01/11/10-tricks-engineers-need-to-know-about-fasteners/ Every source I can find though agrees that split lock washers are useless in any application where the fastener is torqued. The pressure flattens them and they effectively become flat washers with no holding ability. For a split lock washer to work, it has to be under low compression so that there is still some offset in the ends to grab the adjacent material. Interesting how complicated apparently simple things can be Skip

You really should use the hardware as specified by Lycoming. This clamp is critical since it is a single point failure for BOTH mags. For info on split vs. star washer applications, see pp 9-10 of https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19900009424.pdf Skip

Important to make sure you have the new style clamp, proper gasket and correct torque. See Lycoming SI 1508C. Skip

Here's the APS methodology for calculating LOP power using fuel flow that I got back in 2007 at a seminar in Ada. Remember, this is an approximation. Skip