PT20J

Sorry about the flu - that sucks! Since you asked, here's what I think you have to gain. I used to give a lot of flight reviews, and I noticed that the recently minted pilots were pretty comfortable with slow flight, stalls, steep turns, short field landings, etc. And why not? They passed a checkride in the last couple of years where they had to demonstrate proficiency in all that stuff. I also noticed that many more experienced pilots - and especially airplane owners - had grown uncomfortable getting anywhere near the edge of the envelope. Hell, some didn't even like to fly without the autopilot. Proficiency wanes over time with disuse. You may never need to land on a 1500 foot strip. But, you will be a more confident pilot for knowing you could if you had to. There is no need for steep turns in normal flying, but you'll have much better command of the airplane if you can do them within ACS standards. Same with all the standard maneuvers and especially crosswind takeoffs and landings. It's fun to practice, gives a great sense of accomplishment when you can do the maneuvers well, and it's another excuse to fly. And then one day when the engine become disinterested in further toil, and the only place to go is a 1500' strip, you'll be ready. Skip

We have a few like that in the museum DC-3. If you figure it out, let us know -- maybe it will give me a clue to ours

Takes a lot of g's to stall at maneuvering speed - maybe that's your spin problem. The modern Mooneys will have met the normal category spin requirement of recovering from a one turn spin in one additional turn. Beyond that you're the test pilot. BTW, a spin isn't fully developed (i.e., the yaw and pitch rates have stabilized) until somewhere between one and two turns -- until then it's still classified as incipient. Skip

Not sure I understand that. Cherokees have a laminar flow wing and they are kind of slow... Actually, it's almost impossible to make a laminar flow wing as North American found out when they built the P-51 (generally acknowledged to be the first aircraft designed to purposely use a laminar flow airfoil). The wing has to be built to uneconomical manufacturing tolerances and polished smooth in order to not trip the boundary layer. It's not the wing that makes the Mooney have low drag -- it's the small wetted area and general aerodynamic cleanliness of the design. Skip

Seems like everyone wants improved low-speed performance with no effect on the high speed end. Isn't that "something for nothing"? Doesn't that defy nature? Besides, I thought all you "Big Bore" guys were putting around severely LOP at Carson speed boasting about low fuel flows because the big engines guzzle fuel and the stuff has gotten so darned expensive. OK, I'm kidding. Here's a reasonable analysis based on a similar airplane: Vgs_cruise_wide_screen.pdf Skip

Agree there is a lot of value in having a mechanic close to home. If one shop does all the maintenance including the annual, it will get to know the airplane and save you money in the long run. I have done most work on my planes under the supervision of an A&P/IA. That way I know what’s going on. MSCs as well as every shop are dependent on the availability of good mechanics which are in short supply. Some of the biggest screwups on my airplanes have been done at a couple of big name MSCs. I’ve also had great work and great advice from the same MSCs. Bottom line is find a good Mooney mechanic close to home and stick with them. And get personally involved if you have the time and inclination.

A wing with good stall characteristics stalls first at the root to allow continued aileron effectiveness, minimizes the roll off during the stall, and provides aerodynamic warning of the stall (buffeting). A rectangular wing planform naturally stalls at the roots first. Tapered wings as on a Mooney tend to stall at the tips first. Three common methods for correcting this are twisting the wing (washout) so that the tips fly at a lower angle of attack, using different airfoil shapes and thicknesses at the root and tip to achieve the same effect, and stall strips to force the root to stall first. Mooney uses a combination of airfoil changes and stall strips. The strips work by causing flow separation at high angles of attack which stalls the wing section behind the strip. This has the added benefit of creating turbulence over that portion of the wing, and the abrupt ends of the strips create vortices that may impact the tail. Both effects provide the desirable aerodynamic warning of the impending stall. My comment about the roll control purpose of the strips was based in conversations with Rob McDonnell, VP of Engineering, in 1991. But, it also makes sense based on the the location of the strips along the wing. If the purpose of the strips was solely to get the root to stall first - or create turbulence over the tail - the strips would be located closer to the root of the wing as is more commonly done. Skip

Purpose of the strips is to minimize rolling moment. They have to be outboard far enough to have a useable moment arm, but not so far as to affect aileron effectiveness.

I believe that the annual is supposed to follow the manufacturers Maintenance Manual, but perhaps one of the A&Ps can weigh in.

Oil change is on the annual inspection list in the Maintenance Manual.

On the radials, the standard has always been minimum oil temp 40 deg C and CHT 100 deg C before applying significant power. I've always used that. Happens reasonably quickly in our small engines. Lycoming seems to be much more concerned with overheating during ground operation than low temps before takeoff. The IO-360 Operator's Manual says, "The engine is warm enough for take-off when the throttle can be opened without the engine faltering." Still, I think 90 seconds from startup to takeoff is a bit quick, but rentals and flight school airplanes get abused a lot. Still, many such engines make TBO and beyond because, in spite of any abuse, they get used a lot and don't get a chance to rust. Skip

Have you checked the trim manually? It’s common for the Mooney trim system to get stiff. Also, check the carrier bearing where the trim servo attaches to the trim torque tube. It’s supposed to be lubed every year, but is frequently overlooked. If the servo really has gone bad again, it should be under warranty from the rebuild. To make the plane flyable without the servo you’d need to remove the chain from the torque tube and have A&P do appropriate paperwork. Skip

It’s possible for the plating on the ring terminals to oxidize over time and increase the contact resistance of the connection. The star washer digs into the plating for a better contact. If the terminals are tight, it most likely won’t really matter. Other connections on the airplane are in circuits much less sensitive to small voltage drops.

From the description, I'm guessing you have a KCS 55A compass system with KI 525A HSI and KG 102A remote gyro driving a KFC 150 or KFC 200 or KAP 150 autopilot. It sounds like either a broken wire or other issue with the HDG output from the KI 525A to the autopilot. I had a similar problem with an Aspen EFD 1000 ACU driving a KAP 150 and it turned out to be a broken wire at the connector to the KC 191 computer. Steve Chapman at Autopilots Central told me that heading problems are almost never a computer issue.

The low pitch stop is set so that the static rpm is nearly redline with the engine at full power. At this point the governor is out of the picture. During takeoff acceleration, the increased airspeed unloads the blades slightly and the prop wants to turn faster. The governor kicks in to keep the rpm at redline. If the governor fails in flight and the prop goes to the low pitch stop, then the airspeed will drive the prop above redline and the only means you have to control this is to reduce airspeed and/or throttle.

Good observation. In a climb, the weight and lift vectors are out of alignment by an angle equal to the velocity vector angle relative to level. This means that the lift is slightly less than the weight (the difference is made up by a component of the thrust vector). Less lift means less induced drag, and the induced drag is a significant component of the total drag at climb speeds. Think of a jet fighter with a thrust-to-weight ratio >1 in a vertical climb: Lift - and therefore induced drag - are zero. The effect is small for our airplanes, but it is there.

"A lot more heat" would likely be from increased power output at the higher rpm as the increased frictional heating from 200 rpm should not be great. The way to test this is to stabilize in level flight at 2500 rpm and note the airspeed and CHTs and then increase the rpm to 2700 and reduce manifold pressure until you get the same airspeed and note the CHTs.

The Parker rep I spoke with told me that they press in with your fingers and not to use any tools. So, I’m thinking they probably remove easily and can be reused, but I didn’t think to ask. He also said to be sure to grease the lip where it rubs the axle. I don’t know if they are worth it or not. Years ago, I had a J model that sat outside at KSJC. I flew it about 100 hours/year and greased the bearings and seals every year and had to replace bearings about four times in 7 years.

Work in progress. 1994 M20J purchased 6/18. Original paint, original interior, 1125 TT. Engine replaced with factory rebuilt IO-360-A3B6 10/18. Next month, KR-87 and KT-76A will be removed and a GTX 345 installed. Next winter I will work on interior which isn't that bad but looks dated. Paint is a 7/10 and will eventually be redone in a more contemporary scheme.

There is a really good point here. I see a lot of threads on MS and other forums that focus on the technical aspects of interfaces between boxes while overlooking the fact that the STCs control what configurations are legal for certified aircraft. Manufactures can limit configurations permitted by STC for business as well as technical reasons. Skip

email Steve Rue srue@mooney.com and ask him to email you maintenance manual and illistrated parts catalog for M20J. The maintenance manual is two files; second is schematics. The schematics are scans of original drawings that covered several square feet. But, Mooney no longer makes the paper versions available.

I just found out that Parker Hannifin now has molded seals for 5" Cleveland wheels as well as the 6" wheels. Installing these will bring you up to 1950s technology in keeping dirt and water out of your wheel bearings. Stacey Ellis at Mooney confirms they will fit. PRM95-Molded-Bearing-Seal-6-inch.pdf PRM97-Molded-Bearing-Seal-5-inch (1).pdf

Yep, 95 kts at 24 gph. But you can land on the water and take off again!

Well, if you really want to haul stuff -- get a Beaver

Make sure the star washer is between the two ring terminals per the JPI installation manual.