Cervelorod Posted September 6, 2015 Report Posted September 6, 2015 I finished my 6th hour in the F this morning and I am still having trouble with my rollout. The plane seems to want to drift left, and corrections send us into swerves, that have almost put us off the runway ( once ).. I changed my technique with my feet, and that seemed to help some. Hitting the numbers keeps it to a minimum, but it still is very squirrely on rollout. I'm sure part of it is pilot induced, but looking for any tips / techniques if you've seen this issue before. I'm somewhat limited on CFI's in our area. The CFI I used is a good pilot, and has flown just about everything including Mooney time, but I'm sure he is nothing like a Mooney specific CFI. I will be looking for some Mooney specific time now that I can travel away from the home drome for training. Thanks, Rod 6341Q M20F Quote
mike_elliott Posted September 6, 2015 Report Posted September 6, 2015 http://donmaxwell.com/publications/MAPA_TEXT/M20-202 - Eight-Second Ride/EIGHT_SECOND_RIDE.HTM 3 Quote
Rwsavory Posted September 6, 2015 Report Posted September 6, 2015 Get your nose gear checked out by an experienced Mooney mechanic asap. It's not your technique. 2 Quote
bonal Posted September 6, 2015 Report Posted September 6, 2015 (edited) Just a thought yesterday's landing at home winds were variable but with some local gusts just after touchdown we took a quartering tail wind gust and it weather vaned us to the right big time was able to get it under control but took a good bit of effort what were the wind conditions at the time this happened Edited September 6, 2015 by bonal Quote
Yetti Posted September 6, 2015 Report Posted September 6, 2015 landing slower can help also. Not that I do it, but I was told to do it. 1 Quote
bonal Posted September 6, 2015 Report Posted September 6, 2015 Just re read your post and see this is not a one time deal. I agree check your gear Quote
RobertGary1 Posted September 6, 2015 Report Posted September 6, 2015 Could be gear or overacting on the rudder. Are you holding aileron correction into the wind throughout rollout? Agreed that it's good to have everything checkout. It's also part of annual (per the mooney maint manual) Quote
MyNameIsNobody Posted September 6, 2015 Report Posted September 6, 2015 Doubt it is you. Should not be squirelley. Get it check out ASAP. If it is loose (mine was) Laser brass insert and shims work great. Good luck. Be careful. Quote
Andy95W Posted September 6, 2015 Report Posted September 6, 2015 http://donmaxwell.com/publications/MAPA_TEXT/M20-202 - Eight-Second Ride/EIGHT_SECOND_RIDE.HTM +1 Just re read your post and see this is not a one time deal. I agree check your gear +1 could be as simple as a rigging issue, between your rudder, nose gear, and rudder pedals not all being aligned with one another. Quote
Guest Posted September 6, 2015 Report Posted September 6, 2015 Worn nose gear steering "Tee" and incorrect castor angle per SB M20-202 will make landing roll out in a Mooney exiting. Clarence Quote
Cervelorod Posted September 6, 2015 Author Report Posted September 6, 2015 Put it on jacks and low and behold the plumb line is 3/8" behind the axle center. The wheel is just doing what physics says it will do, try to caster around... I am trying to find the actual SB to see what is included in the kit. Sucks to find this on Sunday of a long weekend... Thanks Everyone!!! Rod 1 Quote
Yetti Posted September 6, 2015 Report Posted September 6, 2015 also if you have large feet make sure you are not hitting the brakes. Somewhere in the pattern I think "heels on floor" "heels on floor" and wiggle the rudder. Quote
Guest Posted September 6, 2015 Report Posted September 6, 2015 Put it on jacks and low and behold the plumb line is 3/8" behind the axle center. The wheel is just doing what physics says it will do, try to caster around... I am trying to find the actual SB to see what is included in the kit. Sucks to find this on Sunday of a long weekend... Thanks Everyone!!! Rod Check to see if the upper stop collar on the nose gear has an offset hole, sometimes they do and simply flipping it over will correct the caster angle, failing that you'll need additional spacers under the collar. Clarence Quote
Cervelorod Posted September 6, 2015 Author Report Posted September 6, 2015 Check to see if the upper stop collar on the nose gear has an offset hole, sometimes they do and simply flipping it over will correct the caster angle, failing that you'll need additional spacers under the collar. Clarence M20Doc, I can understand flipping the collar over if it has another hole a different distance from the face, but I can't see in my minds eye how adding spacers will move the axle into trail. Caveat, I have not disassembled the shock disc assembly yet, but from the service and parts manual I can't imagine it.. Thanks!! Rod Quote
Guest Posted September 6, 2015 Report Posted September 6, 2015 M20Doc, I can understand flipping the collar over if it has another hole a different distance from the face, but I can't see in my minds eye how adding spacers will move the axle into trail. Caveat, I have not disassembled the shock disc assembly yet, but from the service and parts manual I can't imagine it.. Thanks!! Rod By compressing the shock discs more, be either flipping the collar or adding shims you change the caster angle of the nose gear. Clarence Quote
MyNameIsNobody Posted September 7, 2015 Report Posted September 7, 2015 Worn nose gear steering "Tee" and incorrect castor angle per SB M20-202 will make landing roll out in a Mooney exiting. Clarence Exciting, while exiting...the runway 1 Quote
Cervelorod Posted September 8, 2015 Author Report Posted September 8, 2015 Took the collar off this morning and mic'ed the distance's on either side. One side had 0.153" and the other was 0.185". Flipped the collar over and the plumb line was centered on the axle. Test flew it and it's a whole lot better. It still has a little twitchiness, but it's not looking for the exit.. I wonder if moving the center of the axle 0.05" behind the plumb line will make it better. M20Doc, it seems like there is some variation in the collar's, what is a good value to shoot for? Thanks to all! Rod 1 Quote
Guest Posted September 9, 2015 Report Posted September 9, 2015 Took the collar off this morning and mic'ed the distance's on either side. One side had 0.153" and the other was 0.185". Flipped the collar over and the plumb line was centered on the axle. Test flew it and it's a whole lot better. It still has a little twitchiness, but it's not looking for the exit.. I wonder if moving the center of the axle 0.05" behind the plumb line will make it better. M20Doc, it seems like there is some variation in the collar's, what is a good value to shoot for? Thanks to all! Rod Whichever combination of stop collar and or spacers gives the correct caster angle as called out in the SB or maintenance manual. Clarence Quote
Cervelorod Posted September 18, 2015 Author Report Posted September 18, 2015 (edited) Mooney emailed me the Service Bulletin, which doesn't call out a ending caster angle, just a beginning measurement and a shim if you are outside that. We manufactured a shim, 0.120" 1.25 dia 4130 cond. N. tubing, and I finally got to test fly it today. PERFECTION... No darting to the left. Can keep my heels on the floor to work the rudder and not feel as though I have to cover the brakes to keep her on the runway. Thanks to all, especially M20Doc. PS - the shim moved the center of the axle 1.15" behind the centerline, it had been 0.375 in front of the centerline. sbm20-202.pdf Edited September 18, 2015 by Cervelorod 2 Quote
carusoam Posted September 18, 2015 Report Posted September 18, 2015 Thanks for filling in those details, CerveloRod. go MooneySpace! -a- Quote
Guest Posted September 18, 2015 Report Posted September 18, 2015 Mooney emailed me the Service Bulletin, which doesn't call out a ending caster angle, just a beginning measurement and a shim if you are outside that. We manufactured a shim, 0.120" 1.25 dia 4130 cond. N. tubing, and I finally got to test fly it today. PERFECTION... No darting to the left. Can keep my heels on the floor to work the rudder and not feel as though I have to cover the brakes to keep her on the runway. Thanks to all, especially M20Doc. PS - the shim moved the center of the axle 1.15" behind the centerline, it had been 0.375 in front of the centerline. sbm20-202.pdf You should be really pleased with how well it tracks down the runway now. And no fear of an off runway excursion. Clarence Quote
electricmike Posted March 24, 2016 Report Posted March 24, 2016 After performing the SB, was it difficult to get the trailing arm back together? I'm having a heck of a time getting all three bolt holes to line up properly. Quote
Guest Posted March 24, 2016 Report Posted March 24, 2016 2 hours ago, daver328 said: It will make it way better. After installing new shock discs we were really squirrelly. Read bulletin. Read Don Maxwells "Eight Second Ride." We looked at that spacer (purchased from Don Maxwell) and wondered "Just how in the world can this little spacer make a difference?" Made all the difference! Also, over the years Mooney has reduced the amount of torque on that vertical bolt (can't recall the specific name) ... and that also makes a difference. See SI M20-109 for nose bolt torque and SB M20-202 for nose gear castor angle. Clarence Quote
carusoam Posted March 24, 2016 Report Posted March 24, 2016 Welcome aboard Electric Mike. Keep in mind some type of work is best left for the pros. (Legal issue) It may help to let people know you are a mechanic or you are working with your mechanic. I'm glad you are here seeking guidance. Best regards, -a- Quote
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