PT20J

Usually a relay or a microswitch. There are a bunch of past threads on this and a current one

Sorry to circle back to the original topic, but I tried putting the flaps down to 15 deg (TO in my MSE) while level at 2000' with the autopilot set to ALT and the airspeed at 105 KIAS. The result was a change in pitch angle to about 3 deg nose down and no change in airspeed.

True, I should have said just below stall.

To minimize the altitude loss in the turn you need to load the wing to just above stall. But, since you will want best glide speed coming out of the turn, I’ve found a good compromise is to fly the turn at best glide speed.

I'd only run it for a few seconds If you test it without a load. Series wound motors are designed to provide high torque to start a heavy load. Unloaded they can accelerate uncontrollably to very high and perhaps damaging rpms.

I think David Rogers and one of his students did an analysis of this maybe 30 years ago. As I recall, the combination that gives maximum radius of operation is a climb at Vx to maximize altitude without getting too far from the runway, a 45 deg bank turn into the wind at just above stall speed to minimize turn radius, and then best glide speed to the runway. Wind and terrain are the biggest variables. Keep in mind that Vx is the speed where thrust/drag is a maximum and will result in a very high deck angle for higher powered, low drag airplanes and isn't that far above stall, so if the engine packs it in and you are at Vx, you will need to aggressively pitch down.

I would look at the schematic to see how it the field and armature leads are connected through the relays and connect it like that.

There is a M20C, E, F, G Service and Maintenance Manual in the downloads section of this site that has schematics. Apparently the older motors have separate field and armature connections. The wire colors are shown in the diagram.

I don't have schematics for a M20E, but I looked at the schematics for the 1977 M20J that also used the Dukes and the motor shows only two wires, a red and a black. I don't know what the other two wires would be for unless yours has separate wires for the armature and the field windings.

I got mine from peerlesselectronics.com

I think Eric’s point is that on a DC motor, there is no “positive” or “negative” wire. If you connect one wire to the positive terminal of a battery and the other to the negative terminal, the motor rotates in one direction. If you reverse the connections, it rotates in the other direction. If you just want to test the motor, try it and see for yourself.

I would buy a used electrical component only as a last resort - who knows how much life is left in it? The Safran catalog still lists the 6041H53 (p 26). I might contact them. I replaced my 28v 6041H220 relays with Safran parts. SE&P_Relay_Catalog.pdf

That’s why WVI is a better data point.

According to the SDS, the active ingredient in Peerco 321 is limonene which comes from citrus peels. I would expect it to work slower but be less toxic than the 3M General Purpose Adhesive Remover which is a brew of aromatic hydrocarbons. I wore chemical resistant gloves and a organic filtering mask when using the 3M product and found it worked pretty quickly if I used the spray cans and followed the directions on the can. It does not seem to affect polyurethane paint.

Can you get data for the 100LL pumps for comparison?

I’ve always found Guy to be very friendly and helpful on the phone.

I used the the Hall effect sensor on my G3X also.

The relays are bolted to the floorboard ahead of the left rear seat.

If there was no motion of the motor and no circuit breakers popped, then the problem is most likely the down limit microswitch or the down relay. When mine did this (but on retraction rather than extension) I isolated it to the relay by jacking the plane, removing the belly panel and tapping the relay with a screwdriver handle which caused the gear to operate.

Why use flaps at all? What do flaps do? Flaps do three things: First, flaps add drag allowing for a steeper approach with power, and using power during an approach aids controllability by providing the ability to control airspeed and descent angle/rate independently. Second, flaps reduce the deck angle allowing better visibility over the nose. And, third (and most importantly) flaps reduce the stall speed allowing for slower and thus shorter landings. So, if flaps do all these good things, why not use all you can get? Are Mooneys easlier to land with partial flap settings? And, are Mooneys so difficult to land that we need to resort to lesser flap settings to make it easier? Judging by the fact that landing Mooneys seems to be a perennial topic of discussion, it appears that many have issues with landing these airplanes. Let's define a good landing as on centerline, with no sideways drift, on the main wheels first. We might further add touching down within say 100 feet of your aim point. Most every competent pilot can do that. But what I think everyone is really after is a soft touchdown which can be more difficult in a Mooney than lesser aircraft. Why? I think there are a number of reasons: 1. When you get a Mooney slowed down to 1.3Vso you are deeper in the region of reverse command (aka backside of the power curve) than many light aircraft and the airspeed is thus unstable in the sense that if it starts to get slow, it wants to get even slower. So, you have use the throttle and elevators more to keep it on profile. 2. Mooneys have a lot of gadgets in the elevator controls. M20Js and earlier have trim assist bungees and later models have a down spring interconnected with the trim and a bob weight. These gadgets add an unnatural control force at low speeds because the spring tension is constant where the elevator forces without the springs would decrease as the airplane slowed. 3. The laminar flow wing has the spar pretty far aft and so the landing gear, which is attached to the spar, is located farther aft of the CG than most other similar aircraft. This is why people sometimes call the airplane nose heavy. But this main gear position has an undesirable effect upon touchdown. At the instant the main wheels touch down, the pivot point shifts from the CG to the main wheels which shortens the moment arm to the tail. This produces a pitch down moment and the tendency to "bang" the nosewheel down harder than intended. 4. The rubber puck suspension system is pretty stiff and not very forgiving if you drop it in on landing even a little bit. Some of these negative aspects can be improved by landing with less flaps. The landing speed is higher so you will be less deep into the region of reverse command. The pitch angle is higher so the flare maneuver does not take as much rotation and is more tolerant of mistiming. But, wouldn't it be better to learn how to land the airplane correctly than to use the "crutch" of using less flaps just to make it easier? It's not that hard. The biggest mistakes I see (and make myself) are not looking far enough down the runway to properly judge height, flaring too high (risks running out of energy and dropping it in) or too low (scoots along in ground effect until it stalls and drops in) and not using a touch of power when it seems it is going to drop in. My best landings are with the power coming to idle just before touchdown and the elevators still coming back as it touches down.

When I have practiced it, I always pull the power and do a slow count to five before doing anything. That’s about the fastest I think I would react. Reaction time should be lower if you brief it because it will be on your mind. But…nothing is certain where humans are involved.

Which seal did you use: the thick walled one or the thin walled one?

If you are concerned about ramp checks, make sure the W&B is up to date and all the AFMS documents are current for the equipment and software versions installed.

I would contact Don Maxwell.

You need to practice at a safe altitude until you know the drill. But, then you really need to practice it on actual departures in varying winds. Only that practice will familiarize you with the view of the ground getting closer with the nose down in a steep turn at low altitude, and the effects on your glide of various wind conditions. After you gain experience with the variables, you’ll know how to brief each departure including the variables of runways available, wind and terrain.