Tom 4536

This is great info. I know that the autopilot corrects the altitude as soon as I reset the altimeter setting, but what I don't know is whether the oscillations start when the altimeter setting is changed. I haven't found any way to stop the oscillations. My plane is in for annual so I won't be able to check this for a while. Setting the Vertical Speed to 0 will be an interesting experiment. My GFC 500 software was updated in the past month and the update did not solve the problem. Thanks for the ideas.

It oscillates only in alt hold. I mentioned the gain control in the old autopilot only to mention that the gain control was available if it needed to be adjusted. It didn't need to be adjusted. To my knowledge the GFC 500 doesn't have a gain control to reduce the oscillations. The old AP worked perfectly until it died. After two attempted repairs by Executive Autopilot I gave up on the old Century 41 AP and had the GFC 500 installed.

Those are the cables that were checked.

The servo cable tensions were checked. When the plane porpoises, the trim wheel does not move but the yokes move slightly. Not sure what the "bridle cables" are. Thank you for your input.

Somehow I missed 81X's post. Thank you. All my servos have been replaced, but the idea of trying alternate static source and also seeing what happens to the FD without the autopilot engaged is a great idea. As soon as my plane is out of annual I will try those ideas. It does appear that the autopilot is overcorrecting. With my Century 41 AP, it was just a matter of adjusting a gain control.

I tried silicone spraying the control column shafts and had all my Garmin software updated in the past month. I don't have anything mounted on my control columns, but my problem persisted after all these measures.

My newish GFC500 does the same thing. I have GI275's rather than a G5. My installer doesn't know of a fix.

T. Peterson: FYI, my LOP cruise engine settings were based entirely on information provided by the very knowledgeable contributors to Moneyspace. The support here has been invaluable. GAMIs are not expensive. They cost about 1amu and my MSC charged about 3 hours labor. My engine runs smoother and I can run LOP.

T. Peterson: I have a 1979 M20K-231 with GAMIs, Intercooler, Merlyn and JPI-900. For the 12 months I have been running LOP in cruise mode. At 11,500, my cruise setting have been 30"MP, 2400RPM, 10.9-11.1gph. This results in TAS of 185-190mph, CHT 320-360, TIT 1580, oil temp 180 (winter) 190-200(summer). I live in Tucson. My plane is at an MSC for annual. I asked the MSC to report back to me as to the engine health after 12 months (200hrs) of running LOP as described above. The MSC reported that the cylinders and valves look excellent and all the compressions are 77-79/80. Hope this helps with your concerns regarding your engine settings.

A year ago when my Precise Flight speed breaks needed repair, Precise Flight overnighted "loaner" speed brakes to me to use. That way we could use their boxes to ship my speed brakes. When the repaired speed brakes were returned to me, I sent their "loaners" back to precise Flight. Worked fantastically.

Interesting, because my other problem in my 231 panel is that my Connext turns off after about 60 minutes. (Foreflight tells me the Connext status.) My avionics installer told me it is a quirk of the FS210. He told me to turnoff the Bluetooth/FS210 circuit breaker when Connext turns off. I find I need to leave the breaker off about 10 minutes before Connext will restart. It acts like it is an overheating problem.

I have started having the problem in my 231 that has a 430, FS210, GI275's and Foreflight with latest updates. While flying with a friend in his 252 with a 430 & 530, FS210, GI275's and Foreflight with the latest updates, he had the same problem. In neither plane did we have any avionics updates. On both planes we have been able to overcome the problem by re-booting the iPads and turning off the avionics master switch and re-booting the avionics. Maybe this is a Foreflight or iPad update problem??

I’ve been flying with a friend in his 252 with a new GI 275 engine monitor. When cruising lean of peak the EIS %HP does not change as fuel flow is changed. Is this an oversight by Garmin or are we doing something wrong? The Garmin Pilot Guide (Ver. H) does not mention that we have to tell the EIS that we are LOP. The JPI 900 in my 231 requires that I tell it I am LOP to get the correct %HP. Thank you.

My 1979 231 has a McFarlan vernier throttle that does not have a center button. My prop & mixture do have a button. I do not use the throttle's vernier during takeoff.

Rene (602-614-0504) owns a Mooney and is a CFI.

This is the first time I have heard of using a reduced RPM for the prop test. I am curious what RPM other MS'ers are checking their prop at. Also how many times they are doing the check. Thank you.

A friend with a 252 burned out a cowl flap motor twice after a recent oil change. Turns out the flap was catching on the new oil filter, which happened to be slightly larger than the recommended oil filter. Seems the correct oil filter is in short supply in some areas.

The 64oz Ocean Spray Cranberry Juice bottle has a large opening and works great.

What keeps the fuel from flowing downhill toward the end of the left tank in a left turn turn? In your video he was able to pour the tea, which shows the fuel will flow from side to side in a turn. Seems that the fuel could flow away from the tank outlet.

Does anyone know how much fuel we need in the left tank to make a left turn to final without running out of fuel?

Make sure you don't have the 3 inch rudder peddle extensions. The extensions give less leg room and put your knees higher. As others have stated, I find adjusting the seat back angle helps a lot.

When my Century 41 failed, it was a week prior to a panel upgrade to GI275s. So while the Century 41 was at Executive Autopilots, the old AI was being replaced with a GI275. The Century 41 had the same problem even with the new AI.

Last year I had the same problem with my Century 41 in my 1979 231. We sent all the autopilot components to Executive Autopilots twice and never solved the problem. I gave up and had a GFC500 installed. Hope you have better luck than I had.

So, on my 231 if I am at 55% LOP and want to increase to 60%LOP do I change the FF with mixture control or by increasing MP?

When I got tired of the hassles with renting I bought a M20K-231. After the 10 hrs of training I felt comfortable and have never regretted my purchase. I can fly as slow as a 172 or as fast as a Mooney, all the time using less fuel than the 172. They say money can’t buy happiness. But money can buy a Mooney which can bring happiness. Maybe you shouldn't show this to your girlfriend or my wife!