PT20J

I’d have gone for the longer one farther away. We were doing aerobatics at 5000’ AGL so we had some altitude to lose, and since we had a lateral control issue, I wouldn’t have wanted to do any significant maneuvering to line up for a field directly below. The safest option is not always the closest. Skip

The Mooney gear could be improved by 1. Replacing the stiff doughnuts with nice soft oleo struts, 2. Moving the main gear closer to the CG so the nose isn’t so heavy, 3. Designing a retract system where both the primary and emergency extension means don’t rely on the same tiny gear train. But, then it would be a Piper Arrow (which — except for the T-tails — is a smooth landing bird). Skip

Perhaps I look at it a little differently because I once had an aileron jam in a C-152 Aerobat coming out of a hammerhead turn. (The problem turned out to be due to a cleco left in the wing, but that's another story). In my case, the airplane wanted to roll hard to the right and it took considerable control pressure to keep it level. We (another instructor was on board -- we were having some fun after work) happened to be pointed at an airport and roughly lined up with a 4000' runway so we declared an emergency and were able to land without having to maneuver. I can tell you that a control problem messes seriously with your mind because what will happen next is completely unknown: What's broken? Will it suddenly let go and become uncontrollable? What will happen if I change speed or configuration? In my case, I flew that little plane down close to the runway without changing airspeed until I had pavement under me and then I slowly reduced power and let it slow and land. I used about 2000' - a record for my longest landing ever in a C-152. So, if I had been flying a Mooney with a baggage door stuck on my stabilizer messing with my elevator, I'd have kept the speed up, left the flaps alone and not messed with the gear until the last minute. The only rule that matters about when to put the gear down is that it has to be down and locked before the wheels touch. Skip

Anyone had seats and/or interiors redone by Oregon Aero recently? If so, how did they come out? Skip

Had to get a new magneto coil for the right engine in the museum DC-3. Found a new old stock one still in the can (kind of neat, solder-sealed just like a sardine can complete with a key attached to open. Inside was a new coil wrapped in the latest news from WW II). A lot of airplane parts kick around for a long time. Skip

That’s the best way to do it. Aircraft tails are designed for distributed loads so be careful if you load the tail to raise the nose. Shot bags or something similar are best. Cessnas have had lots of cracking problems by people man handling the tail. (There is a safe way to do it on a Cessna, but you have to push on a tail bulkhead and not on the stabilizer). Skip

Why not just deal directly with JPI?

Perhaps I wasn’t clear. 1. The emergency mic jack won’t work with a headset boom mic because there is no PTT since the jack is designed to be used with a handheld mic that has an integral PTT. 2. The most failure prone component in the system is the yoke PTT since it is a small mechanical switch that gets used a lot. 3. If the yoke PTT fails, it would be nice to continue to use the headset. This could be done by plugging the headset plugs into the emergency jacks IF a PTT were added to the emergency mic jack (which is trivial - just wire a momentary pushbutton between tip and sleeve and mount it somewhere convenient). I was just curious if anyone had done this? Skip

My 1994 M20J has emergency microphone and headphone jacks located on the center console. I believe that is standard with most mid and long body Mooneys. The microphone jack is intended for use with the handheld mic which has an integral push to talk switch. From my experience, the most likely component to fail is the sub-miniature PTT on the pilot yoke in which case it would be nice to just plug the headset into the emergency jacks. The problem with this is that there is no PTT to enable the headset microphone. Has anyone thought to add a PTT switch to the emergency microphone jack? Skip

I'm curious: Most everyone that has Powerflow grumbles about how much of a pain it is to disassemble it every year to lubricate the slip joints. Has anyone NOT done this and noticed any problem (or not had any problem)? The reason I ask is that the stock system also has slip joints. Some people don't do any maintenance on these. A lot of mechanics squirt some mouse milk or Aerokroil in them whenever the cowling is off (that's what I do) and never have a problem. I had an issue with the tail pipe hitting the cowl flap and thought it was due to the ball joint binding. I took it apart and lubed it with C5-A (MIL-PRF-907F, latest version of what Powerflow calls for) and that made it rotate freely. Fifty hours later, I checked it and it was just as tight as before. So, I'm not convinced that the lubrication buys anything after a few hours. The only requirement to disassemble and lubricate annually I see is in the form of an ICA ,and ICAs are not required to be complied with for part 91 operations unless they show up in a limitations supplement to the AFM. So, I'm wondering if the Powerflow really needs this extra lubrication. Skip

The Powerflow rep at MooneyMAX said that the J exhaust is pretty efficient and that there isn't much improvement to be had from a PF. Skip

From Bob Kromer: Here are some thoughts. I was the one who did factory flight testing investigating what happens when a baggage door is left unlatched prior to flight. The test airplane was an M20K. I had a mechanical system installed where I could unlatch (from the shut position) the baggage door from the pilot’s seat during any phase of flight. We discovered absolutely no adverse handling qualities or aerodynamic issues when the door is left unlatched and should open in flight. Interestingly, several times when the door was unlatched from the inside it just stayed in position. But if a baggage door is left shut but unlatched and does come open during flight, it most likely will open at rotation during takeoff. The change in angle of attack during rotation allows the airflow in the vicinity of the baggage door to lift it upward. It’s a noisy distraction when it opens, but if ignored it is easy to return for a normal landing. There were no adverse handling qualities encountered in any of the phases of flight we tested where we opened to door, including takeoff, climb and cruise. The key thing we took away from our testing was if someone doesn’t latch the baggage door on preflight, it almost always opened very early in the flight. Usually during rotation or initial climb. And it was a non-event. Now, having the baggage door depart the airplane is another matter. How could this happen, especially at lower takeoff and initial climb speeds? I am aware of only one other situation where the baggage door actually departed the airplane when it opened. I believe it was for an M20K that we repaired at the factory. But this door came open during a high speed descent. When it opened, the heavy air loads at 160KIAS ripped the door from the fuselage and it struck the vertical tail. As it flew past, the baggage door struck the vertical fin and cut the skin, but with no further structural damage. The airplane came to us at the factory and we repaired both the tail and the baggage door/fuselage. We did a thorough inspection of the baggage door and cabin structure before and after the repair and found absolutely no issues that would cause a properly latched door on this airplane to come open. Incidentally, the owner later admitted that someone was retrieving luggage from inside the airplane during descent when the door came open. We think somehow that inadvertently unlatched the door from the inside, causing it to open during the high speed descent. So how could a baggage door on the airplane shown below actually come off at such a low speed and hit the tail? I don’t know, the air loads at takeoff and initial climb speeds are not that great. Was the baggage door hinge broken or worn out? Did the pilot fly really fast in a hurry to return to the airport? A normal baggage door, even if it opens, just doesn’t depart the airplane this easy. I’m happy it turned out okay. Bob

There is a suction screen and a filter screen. Suction screen is at bottom of sump. Filter replaces the filter screen on the accessory case. Skip

61.129 specifies the cumulative experience you must have logged as a pilot before your practical test. It doesn't refer to previous certificates or ratings; just logged experience. Skip

Thanks, Paul, I missed the placard; I was just looking at the text. Of course, the placard is conveniently located on the inside of the baggage door, where to read it you either have to be in the baggage compartment or stick your head inside the opening and rotate your neck 180 degrees. BTW, I’m not doubting anyone who claims it was latched properly and still came open. I’ve been around long enough to have seen many things happen that don’t seem possible. I’ve learned to always either have the door fully opened or shut and latched. If it’s only halfway open, I bang my head on it coming down off the wing. If I close the door but leave the latch open, I skin my arm on the latch climbing up onto the wing. Pain and blood are great teachers, I have found. Skip

No, this is correct. If you have one altimeter and airspeed you know how high you are an how fast you are going. But, if you have two, you're never quite sure. With three, you can vote and the majority wins!

Interesting idea. But, let’s think about it. One thing about air is it just doesn’t like to flow backwards. Air flows from high to low pressure, so to get the air to reverse course, there would have to be a strong source if suction behind the handle. But this would tend to hold the handle closed rather than open it. And, if the air did reverse course and get under the handle somehow, where would it go? The depression that the handle rests in would be a dead end. And, air at Mooney speeds is essentially incompressible, so it won’t “bunch up” in there. Since it can’t get out and it can’t compress, it won’t go in and it won’t reverse flow. Skip

Looks that way from the three-view, doesn’t it? But, aerodynamicists think of a wing in terms of the quarter-chord line. The aerodynamic center (the point at which the pitching moment does not vary with angle of attack) lies very close to quarter chord and using that point as a reference simplifies calculations. So geometrically, a tapered wing with a straight leading edge and a forward swept trailing edge would have a quarter-chord line swept forward from a line perpendicular to the wing root. Skip

I looked at the SB and also my 1994 J AFM and I can't find anything about locking the baggage door. I think it's a good idea though, because after playing with this I cannot see how the darn thing can come open unless one of the handles is not fully closed,and it's unlikely (though not impossible) that you will leave the handle open if you lock it. Skip

Check the dimensions and areas chapter of the service manual. Wings and tail surfaces all have a forward sweep. Skip

That's the one you have now.

Spencer claims to have stock http://spenceraircraft.com/14oz-aeroshell-grease-5.html Skip

I happen to have the interior out of my 1994 M20J and I spent some time looking at the baggage door hinge and lock this afternoon. This picture shows the door with the exterior handle in the open position: Here's what it looks like with the exterior handle in the closed position: Note how far the latching pins protrude in the latched position. There is no way that the door is going to open if the pins are engaged unless perhaps the hinge gives way and allows the door to shift. Here's a shot with the interior emergency handle pulled open: I labeled two springs, A and B. Spring A creates an over center force to hold the mechanism either open or closed. In addition, Spring B acts to hold the pins in the latched position and did so (albeit less forcefully) even when I removed spring A. I noticed that to open the door with either the inside or outside latch, the lever has to be pulled forcefully over center. Even if the hitch pin was removed from the inner lever, I don't think the door could open unless something pulled on the lever with enough force to compress spring A and move the mechanism over center. The piano hinge is riveted to the tailcone skin and the door. It is recessed slightly so that the tailcone skin retains the hinge pin. The design seems very secure. I don't see how it could open unless something was broken or it wasn't latched. But, in cases where it is not latched, I would expect that it would open on takeoff as others have reported. In this case, there was a delay. Skip

I don't know. I went to the museum on my field that does a lot of paint work and they mixed me up a cup of their favorite epoxy primer for painting tubes. It's similar to the factory primer in that it has a semi-gloss finish which makes it less porous than most primers. It's probably not the best primer for painting over but good if you are going to leave it exposed. Skip

I don't know but the only thing I ever used it for was wheel bearings. Mooney and Cleveland now recommend SHC 100. You might try that but if you switch you need to clean out all the old grease. I've standardized on the following greases (per the service manual): Wheel bearings: Mobil SHC 100 Trim system Aeroshell 7 Control guide blocks Aeroshell 7 Landing gear zerks Aeroshell 22 Landing gear and flap actuator ball screws Lubriplate 630-AA Skip