M20 Ogler Posted January 28, 2022 Report Posted January 28, 2022 With PC on my Mooney will go into a 4 minute 360 degree turn to the right. If I pull the PC button out of the yoke (that disables PC right?) the airplane will begin increasing bank to the right and will be at 45 degrees after 10 seconds. I did not let it go further than that. I wonder of this is a rigging issue or if there is something going on with the PC system. Any thoughts? Quote
Marauder Posted January 28, 2022 Report Posted January 28, 2022 With PC on my Mooney will go into a 4 minute 360 degree turn to the right. If I pull the PC button out of the yoke (that disables PC right?) the airplane will begin increasing bank to the right and will be at 45 degrees after 10 seconds. I did not let it go further than that. I wonder of this is a rigging issue or if there is something going on with the PC system. Any thoughts?If you have the PC disabled and it still banks, it could be a rigging issue. A major fuel imbalance could also make it bank. If you are in level flight, with the PC disengaged, do the ailerons look the same? I have had two rigging issues over the years. One caused by a flap that wasn’t rigged correctly and the other due to one of the landing gear being slightly in the slipstream. Sent from my iPhone using Tapatalk Pro Quote
Yetti Posted January 28, 2022 Report Posted January 28, 2022 On some Brittin TC there is an adjustment knob that will turn the plane left or right. Also if you have an Accutrak make sure it is off. it also has a turn left or right knob. Quote
Jcmtl Posted January 28, 2022 Report Posted January 28, 2022 Mine does the same thing. Check your flap rigging or check if the trailing edge of the right side aileron is bent downwards. Quote
0TreeLemur Posted January 28, 2022 Report Posted January 28, 2022 Sounds like rigging to me. The PC system attempts to compensate for it given that it helps when activated. Left bank trim on the TC should allow full compensation unless your aerodynamic issue is more than it can compensate for. With the PC system disabled the rapid banking tendency you're seeing indicates something out of adjustment with control surfaces and not a PC system issue. 1 Quote
FlyingDude Posted January 28, 2022 Report Posted January 28, 2022 Check your PC hoses, even if it means opening many access panels on the wing and belly. There are bend points. If it kinks, the air restriction will favor one boot over the other... Quote
Hank Posted January 28, 2022 Report Posted January 28, 2022 22 minutes ago, FlyingDude said: Check your PC hoses, even if it means opening many access panels on the wing and belly. There are bend points. If it kinks, the air restriction will favor one boot over the other... Same thing is a rubber servo sleeve tears. Quote
M20 Ogler Posted January 28, 2022 Author Report Posted January 28, 2022 (edited) This picture makes my HS appear as if it’s not perfectly parallel to the wing. I’m assuming this is not the way it’s supposed to be. IDK if that would affect my roll to the right Edited January 28, 2022 by M20 Ogler Quote
carusoam Posted January 28, 2022 Report Posted January 28, 2022 There are so many ways to approach taking a pic…. More ways to have a rubber donut make a difference… Doing controls rigging is in degrees… Fortunately donuts don’t make a difference in flight… if the button of the Brittain is pushed, or taken out… the Brittain is disabled… or the gyro is dead, or the vacuum line has been disconnected…. If things are rigged perfectly, and the Brittain is disabled… a slight imbalance of weight from left to right will cause the plane to dip a wing… Once a wing dips, the spiral starts to increase… there won’t be a chance landing in a field miles away if the pilot is not awake, or have an operating wing leveler… The pilot side is already heavy, by having the pilot sitting there… To see a noticeable difference… the air has to be extremely smooth… above 3-4 k’ agl on most days…. Spend a flight burning off fuel from the heavy side. See if it comes neutral… Many planes have a trim tab on the rudder…. LBs have an electric rudder trim… When fuel or people cause a heavy wing…. Use the rudder trim to adjust it up… The challenge… things are always changing, different day, different people, different fuel load…. Without an operating wing leveler or a copilot… the plane will only follow the magenta line for a minute or two on its own… before enough fuel burns off to start drifting again… in the meantime… when really close to being balanced… you can use weight shifting techniques to stay on the magenta line… (Experiments done using a 1965 M20C, with rigging last adjusted in 1965…. Magenta line was an LCD black line… with the gps giving distance from the line in feet…) Check to see how the tail tab is bent… If the pilot is on the slim side… somebody may have adjusted it to meet their needs previously… Don’t expect the plane to fly straight on its own… too many variables for that. It should be able to fly straight for about a minute when everything is really well balanced… Finding that balanced minute may require burning most of the fuel out of the heavy side… PP thoughts only, not a rigging genius….. -a- 1 Quote
Guest Posted January 28, 2022 Report Posted January 28, 2022 41 minutes ago, M20 Ogler said: This picture makes my HS appear as if it’s not perfectly parallel to the wing. I’m assuming this is not the way it’s supposed to be. IDK if that would affect my roll to the right I’d be surprised if the tail was on crooked. A well rigged airplane should fly straight on its own in still air for a little while. It sounds like you need to correct the rigging first to see how the PC copes in flight. Clarence Quote
M20 Ogler Posted January 28, 2022 Author Report Posted January 28, 2022 I’m about a ten minute flight from KSCK maybe I should call Top Gun and tell them what’s going on. They are a Mooney service center right? Quote
Joshua Blackh4t Posted January 29, 2022 Report Posted January 29, 2022 I have an aileron trim tab on mine. We fitted it straight away after I brought her home, 13 hours of hand flying holding to the right. The mooney manual recommends bending the rivet line to make a trim tab effect, but my mechanic preferred to make a 30mmx50mm (1.5inch x 2 inch) aluminium plate and rivet it to the trailing edge with the existing rivet holes. It took about 3 flights to get it right, but now it flies hands off, or with one finger pressure every few minutes in still air. 1 Quote
M20 Ogler Posted February 4, 2022 Author Report Posted February 4, 2022 It does appear as if my right aileron is trailing slightly above neutral when I’m hands off the yoke. I wonder if the rod end on the aileron pushrod can be turned to eliminate that. There is some free play in all my control surfaces. Looking to find out how much is allowed and how to measure. IA says it ok for now but keep an eye on it Quote
carusoam Posted February 4, 2022 Report Posted February 4, 2022 Measuring rigging is done with travel boards… Found at the local MSC… Done with expertise… The tools alone, probably won’t help enough… time used become excessive… PP thoughts only… -a- Quote
Guest Posted February 5, 2022 Report Posted February 5, 2022 3 hours ago, M20 Ogler said: It does appear as if my right aileron is trailing slightly above neutral when I’m hands off the yoke. I wonder if the rod end on the aileron pushrod can be turned to eliminate that. There is some free play in all my control surfaces. Looking to find out how much is allowed and how to measure. IA says it ok for now but keep an eye on it Mooney doesn’t/didn’t publish free play limits for ailerons, so you can argue that no play is allowed, or you can argue that since they didn’t publish a limit, it doesn’t matter. Some play is inevitable with the number of rod end bearings in the system. Clarence Quote
Shadrach Posted February 5, 2022 Report Posted February 5, 2022 The way I read this you have a PC Problem and a rigging problem. Plane should be rigged for wings level without PC. PC is complimentary to a properly rigged aircraft, not a fix for one that is poorly rigged. I you’ll start with the vacuum hoses behind the panel. They are often neglected and have a useful life about 6-8 years. Work your way out from there. Quote
Rick Junkin Posted February 5, 2022 Report Posted February 5, 2022 On 1/28/2022 at 5:26 PM, M20 Ogler said: This picture makes my HS appear as if it’s not perfectly parallel to the wing. I’m assuming this is not the way it’s supposed to be. IDK if that would affect my roll to the right @M20 Ogler Take a close look at your elevators. Are they symmetrical? I don't trust the picture, but if you were 100% square on when yo took it then the right elevator appears to be deflected up with respect to the left elevator, which would induce a right roll. You can easily measure this with a digital level, just make sure the elevator doesn't move between measuring the left and the right. If it's bad enough you may be able to eyeball it. Mine were out of symmetry by about a degree and gave me a roll rate of about 2-3 degrees per second. It went away when I had them adjusted. Let us know what you find! Cheers, Rick Quote
Bob R Posted May 9, 2022 Report Posted May 9, 2022 On 1/28/2022 at 9:19 AM, M20 Ogler said: With PC on my Mooney will go into a 4 minute 360 degree turn to the right. If I pull the PC button out of the yoke (that disables PC right?) the airplane will begin increasing bank to the right and will be at 45 degrees after 10 seconds. I did not let it go further than that. I wonder of this is a rigging issue or if there is something going on with the PC system. Any thoughts? I just re-rigged my E. Made a huge difference. Quote
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