PT20J

From the Airplane Flying Handbook

Mooney has not sold parts direct for 30 years.

Factory service center does maintenance and repairs but does not sell parts. The only way to get new parts from Mooney is through a MSC. Frank Crawford will verify parts numbers and Mooney stock, but not parts pricing since each MSC sets its own markup.

Both Lycoming and Continental recommend setting power with manifold pressure and rpm to some max cruise power (75% for Lycoming, 65% for Continental) before leaning. Why? Because it is absolutely safe. That works acceptably ROP because there isn’t that much power drop off when leaning, but once you lean past peak EGT the power falls off rapidly and the engine will be putting out much less power. You can get the power back by increasing the MAP to increase the fuel flow to a value that gives you the desired power setting. The Big Mixture Pull is just a way to simplify the process. This works because the BSFC vs BHP curve is approximately linear over a wide range of LOP mixture strengths allowing BHP to be determined primarily as a function of fuel flow. The theoretical basis for the multipliers based on compression ratio that APS teaches for calculating HP from LOP fuel flow is that the thermal efficiency of an internal combustion engine increases with compression ratio (the derivation is in every introductory thermodynamics textbook). Thus, at higher compression ratios, the engine extracts more work from the fuel, or alternately, the same power with lower fuel consumption. Skip

At two Part 135 operators I flew for, our FAA-approved checklist called for a run up on the first flight of the day only and we never checked the fuel selector.

According to the M20J Service Manual, for the Eaton style actuator, the distance between the ball screw barrel nut and the mechanical stop when the gear is down should be .050 - .100 inches. I'm not sure what that translates to in linear motion of the retraction rods -- depends on the mechanical advantage of the bell crank -- but I doubt the rods would get bent if everything were adjusted correctly and the down limit switch failed. The manual allows up to a 325 in-lb preload torque when the gear is electrically lowered (this is higher than the 250 - 280 in-lb when manually lowered to allow for some overrun). But, if it is true, as it appears to be, that there is no mechanical down stop on a Dukes actuator, then a failed down limit switch and resulting overrun would bottom out the bungee springs out at the gear wells. When setting up the gear, the starting preload on the springs is set by only two turns of the rod ends on the retraction tubes -- not much linear distance. Skip

There seems to have always been a mechanical up stop. The mechanical down stop seems to be a feature added to the Eaton actuator. Not sure about the Plessey. The Dukes doesn’t appear to have a mechanical down stop. So I guess if the down limit switch fails, you get bent tubes.

I think I must have done it correctly the first time because it just worked. Then, I got a new iPad and had this problem. I tried it three times with the same result before I thought to reverse the order of acknowledgement and got it to work. Apparently, I proved the old adage that repeating the same thing over and over and expecting a different result is a form of insanity. I sent a note to ForeFlight support. Skip

Connext is a generic term Garmin uses for wireless connectivity. But, not all devices with Connext capability share the same information. The Bluetooth connections allow transfer of flight plans between the iPad and the G3X and GTN. GPS, attitude and ADS-B In come from the GTX.

Did you mean a GTN 750? Did you refuel? The totalizer function of the G3X asks about fuel used after refueling if you don’t reset it. If a fuel sender has gone bad, it might confuse it. Might be a problem with the GEA 24. Is it powered and are all the other engine parameters correct? There was a software update a while back that allows the GTN to get fuel quantity and fuel flow from the G3X EIS. Skip

I paired the new iPad with a Garmin G3X Touch (GDU4XX) and a Garmin GTX 345. Both the iPad and the Garmin equipment showed CONNECTED, but there was no Garmin data transfer to or from the iPad and the ForeFlight Devices tab showed "No supported devices connected." I experimented and found that it only works properly if the pairing request is acknowledged first on the Garmin device and then on the iPad. If it is done in reverse order, it pairs and shows connected when all devices are operating, but data will not transfer. These connections are Bluetooth directly between the iPad and the Garmin equipment -- I don't have Flight stream. Skip

Paul is most likely right about the tubes being permanently deformed, but if it were mine I would get the pressure off of them and see. The tubes appear to be the same -- if you look at the Units/Assy column in the IPC for item 22 you'll see 2. Skip

I wonder if they are truly bent or just bowed under compression. It’s hard to tell from the angle of the photo. Steel has a pretty high elastic limit and I don’t see any kinks. Probably a good idea to get it on jacks and get the load off and see. They might spring back into shape. I don’t know if the Dukes-equipped planes have mechanical down stops. I don’t see them on the actuator or see reference in the service manual. The Eaton version can’t overdrive the gear by much due to the mechanical stops, but maybe the Dukes can which would make the whole thing depend on the down limit switch. Anyone familiar with the Dukes know? Skip

It also looks like one of the mechanical down stops is missing and the other one is bottoming out. And the nose gear doors don’t look tight when retracted.

They’re a lot easier

What did you use to remove the goo from the intake duct?

It seems that a lot of folks on BeechTalk have switched from Brackett to Donaldson air filters. It avoids the sticky Brackett goo and some are claiming higher MAP on takeoff and better filtration. Any pireps from Mooney owners?

Nice, Guy.

ForeFlight has a legacy W&B and a newer one that integrates with flight calculations that I haven’t tried. The legacy version doesn’t have profiles, so you can enter whatever you like. team@foreflight.com is very responsive. If there is an error, I would send a copy of your POH to them and they should fix it. Skip

I asked Bruce Williams how the GFC 600 works. He sent me this video clip. Note that the equivalent GFC 600 mode is VPATH. The GTN auto switches to VLOC after the IF. The autopilot captures TOD and follows the GTN vertical track down to the GS intercept altitude at the FAF at which point it switches to GS. I would expect Garmin to make the GFC 500 do the same thing when transition to approach is approved.

The EDM 830 is not primary, so the factory gauge and sender remain in place. This means that the JPI sender has to be located somewhere else. The usual installation is at the front of the engine by removing a pipe plug from an oil gallery. This point is farther from the oil cooler and hotter than the factory location at the rear of the engine. Cowl flaps don’t have much effect on oil temperature on my M20J.

Manifold pressure gauges do become inaccurate and, in my experience, they always read low. I used to fly float Beavers for a Part-135 operator. Every year some pilot would remark that a particular airplane was sure a lot faster than the others. We all used 28"/1900 rpm for cruise. I asked if it seemed to burn more fuel and invariably the pilot would admit that it did. At the end of the day, I would check the manifold pressure gauge on the "fast" airplane and find it reading about 1.5 inches low. After the service department replaced the gauge, the pilot would complain that something happened because now the airplane wasn't fast anymore. Skip

My M20J has vents in each footwell sidewall that are attached to NACA scoops. I used the duct seal on the wemac flange to seal where it attaches to the scoop in place of the original sealant.

I just had my M20J boost pump overhauled by Aeromotors ($450). It’s much quieter now though it wasn’t leaking and made pressure before. But, after 30 years, I figured it was time. Sounds like a new manifold pressure gauge is in order. First thing I would try is replacing the batteries in the headset. If that doesn’t fix it I would reset the software by telling the phone to forget the Bose. Then turn the phone off (not just locked; power it down) and restart it and the pair it with the Bose again.