Fly Boomer

What ap are you using for that?

Glad you found a possible cause. As others have suggested above, I would disassemble and flush not just the tanks, but the tanks and everything downstream from there. No telling where that crud has migrated to.

Just have to stay in front of it. Nice stats!

By "overlay" do you mean a thin carbon fiber sheet that is glued or screwed to the underlying aluminum panel?

This is good stuff. I will try this process as you described. BTW, when I am exercising the autopilot in the hangar, I activate my electric standby vacuum pump to spin the attitude gyro. Thanks again.

Motivation seems simple: bust a medical, and you are probably screwed for life.

Thanks Jake! So if the yoke is full forward (resting position on the ground with an M20K), auto trim should start rolling in nose-up trim? I'll see if behavior changes if I hold the yoke back during PFT. Does the "slow to start" behavior with the pitch rocker on the KC-191 (as well as over-run when the rocker is released) sound normal?

I would be surprised if leveling before each preflight is a requirement. Also, I guess I would have expected King to have said something about leveling in their documentation. I need to get back to the airplane and nail down its behavior better.

@Jake@BevanAviation does this PFT failure sound like anything you have seen?

FAA Airmen database.

When I use the rocker on the autopilot head to change pitch, it seems slow to react -- both to start, and to stop once started. I feel like I'm chasing it up and down.

That sounds right. Every time I run my checklist, my notes get better, so I'll have to verify.

I meant to say I checked that the autopilot would respond to changes in the the heading bug, and after that, I'm reading my checklist for the next step, and the trim wheel starts moving -- apparently uncommanded. Not fast, but I can't figure out where it thinks it's going.

Question for any of you who have ever flown behind a KAP-150. I'm creating a PFT (Pre-Flight Test) checklist from the Pilot's Guide, and getting behavior that I don't understand. K-model sitting in the hangar. GPU plugged in; Master on; Radio Master on; Elevator Trim on; Standby Vacuum Pump on; GNS-430 on; give the gyros a few minutes to stabilize. Tap the Test button, all annunciators on both the KC-191 and KAS-297b light up; flashes and beeps five times; AP annunciator blinks; Trim annunciator goes off. AFAIK all these automatic gyrations are expected. MET (Manual Electric Trim) on yoke: Left side up and down, wheel doesn't move BUT I can't overpower the MET using the wheel. Right side up and down, wheel doesn't move, and turns freely. Wheel does not turn when holding AP DIS/TRM INT button on yoke. Again, AFAIK all is well (except for being able to overpower the MET when left side of trim button is used). Turn on AP ENG button on KC-191 (pitch hold/roll level mode), and box the controls to assure I can overpower autopilot -- all okay. Add HDG on the KC-191, and the yoke turns left and right to follow the Heading bug on the KI-525 HSI -- all okay. Now, after about 5 seconds, the trim wheel starts creeping slowly nose up. Takes at least a minute to get all the way nose up. I'm not sure what it's headed toward, but in flight this would not work. Also, if I use the Up/Dn rocker on the KC-191, nothing happens for 3-5 seconds, and then the trim starts to move. If I take my finger off the rocker, the trim CONTINUES for at least another five seconds, or until the trim is against the stop either up or down. Again, in flight this won't work. Sorry for the long-winded explanation, but I'm hoping someone familiar with this autopilot can suggest something to look at.

This is Maxwell's hot start procedure, but it may suggest an approach: https://youtu.be/jbRYqS-fRo0