WaynePierce Posted October 12, 2021 Report Posted October 12, 2021 So, I just got the plane back from annual and one of the things I had them double check and I went to the shop to observe and see for myself, was the steering linkage. I had quite an unexpected jaunt to the left of a great big, wide runway recently I also, on every take-off get a little "loose" right before I leave the tarmac. Everyone was very helpful in recommending the 8 Second Ride, and having the linkage looked at. Mine was fine, no slop, the alignment with the rudder was also correct. Then I watched a video on YouTube with a CFI-I and a student in the left seat of a M20J, and the CFI-I mentioned to the student he may need to put slight pressure on the yoke to keep the nose down on take-off. I never thought about my "squirrely" handling on take-off possibly being due to the front getting light right before take-off speed is reached. I will play with the trim and see if making it a little nose down may make the handling better. Where do you other "J" drivers trim for take-off? Center of the block, top of the block or bottom of the block? Quote
A64Pilot Posted October 12, 2021 Report Posted October 12, 2021 (edited) it’s going to vary with CG, but with just people in front my trim is above the mark. I disagree with holding the nose down after landing though, I hold mine off as long as possible for aerodynamic braking, and having more tail wheel than tricycle time not holding the yoke aft all of the time just feels wrong. I’ll relax pressure I was holding up after landing, but never push. In my opinion take off trim is correct when if left alone the aircraft will takeoff and climb at the correct angle all by itself Edited October 12, 2021 by A64Pilot 3 Quote
PT20J Posted October 12, 2021 Report Posted October 12, 2021 It is not a good idea put forward pressure on the yoke during takeoff. The M20J is plenty nose heavy and adding forward pressure will make the steering even more sensitive as the wings begin to take weight off the main wheels eventually leading to a “wheelbarrow” loss of control if you carry it too far. I find that former Mooney factory test pilot Bob Kromer’s technique of holding about 5 lbs. of back pressure during takeoff leads to the smoothest rotations. You need to relax the pressure as the pitch comes up to climb attitude and then the trim will hold it there if you had it set right. If your squirrely handling is only on takeoff and not landing, then the airplane is probably fine. I would try Bob’s technique. It is normal for the steering to get more sensitive as speed increases. Remember also that the steering and rudder are hard connected unlike many other airplanes that have bungees, so if you are holding rudder for a crosswind correction you need to let the rudder center when the nose wheel touches down. Also, there are springs connecting the ailerons and rudder, so aileron input has some effect on steering. Skip 8 2 Quote
Ragsf15e Posted October 13, 2021 Report Posted October 13, 2021 Exactly what skip said ( @PT20J). Also remember that approaching takeoff speed, your rudder is pretty effective. Being light on the nose is not going to cause directional issues unless you cause them with the rudder. On the other hand, being heavy on the nose can cause problems as skip described. 1 Quote
Mooney in Oz Posted October 13, 2021 Report Posted October 13, 2021 1 hour ago, WaynePierce said: Where do you other "J" drivers trim for take-off? Center of the block, top of the block or bottom of the block? When there is only me, top of the block. 1 Quote
WaynePierce Posted October 13, 2021 Author Report Posted October 13, 2021 (edited) 1 hour ago, A64Pilot said: it’s going to vary with CG, but with just people in front my trim is above the mark. I disagree with holding the nose down after landing though, I hold mine off as long as possible for aerodynamic braking, and having more tail wheel than tricycle time not holding the yoke aft all of the time just feels wrong. I’ll relax pressure I was holding up after landing, but never push. In my opinion take off trim is correct when if left alone the aircraft will takeoff and climb at the correct angle all by itself The "squirreliness" is only during take-off. I think the dash to the left side of the runway may have been a brief crosswind gust upon landing. Normally the landings are pretty firm and down the center. Edited October 13, 2021 by WaynePierce Quote
carusoam Posted October 13, 2021 Report Posted October 13, 2021 The block depicted on the trim setting… actually has meaning. When you calculate the WnB… are you at the front or the back of the envelope? Front of the envelope… set the trim at the top of the box… Back of the envelope… set at the bottom of the box… As PIC, be ready for the trim to not be an exact method of setting T/O or climb speed… Mooneys don’t depart the runway on their own… They can get squirrely if you wait for the plane to fly itself off… Somebody in the design department selected the gear height and leg lengths to make this work the way Bob Kromer suggests… + if it comes off the runway on its own… expect that it will be trimmed very nose light, probably come off early with any pulling on the yoke, and will climb closer to the stall speed… As PIC… you are more than welcome to experiment with these settings to get a feel for how it all works… just be extra aware of your IAS, wind conditions and know your stall horn is working properly… PP thoughts only, not a CFI… Best regards, -a- Quote
ZuluZulu Posted October 13, 2021 Report Posted October 13, 2021 3 hours ago, WaynePierce said: Where do you other "J" drivers trim for take-off? Center of the block, top of the block or bottom of the block? I was taught bottom of the block by a 20-year M20J owner CFI. Quote
PT20J Posted October 13, 2021 Report Posted October 13, 2021 3 hours ago, WaynePierce said: Where do you other "J" drivers trim for take-off? Center of the block, top of the block or bottom of the block? There will be variation according to CG and individual airplane rigging. In my airplane with just me in it I set takeoff trim so that the top of the black indicator is at the top of the takeoff window. Quote
A64Pilot Posted October 13, 2021 Report Posted October 13, 2021 (edited) ANY GA aircraft will take off on its own if the trim is set to, there is no negative angle of attack or other force that must be overcome to initially get one off of the ground. I pull back pretty heavily, pretty much full up initially until the nose wheel comes unstuck and then hold it off by slowly releasing back pressure until she flies. Pretty much a soft field technique, but I’m coming off of grass, and all nose wheels are inherently weak, and taking the weight off of them on a field that may have a hole etc is not a a bad idea. ‘If I flew off pavement, I’d likely do the 5 lb method, which is pretty gentle, but gets it flying quicker than letting her fly herself off.If your having to horse the thing into the air and hold back pressure to climb, then your trimmed too much nose low ‘Simply put, trim sets an airspeed, say 85 kts for example, power above required to maintain level flight at trim speed and the aircraft climbs, less and it descends, speed will vary some, but should remain about the same. Bottom line after takeoff and in the initial accelerating climb, very little force on the yoke should be required, now when gear and flaps come up it’s normal to need to trim nose down as the center of lift moves with flap retraction Edited October 13, 2021 by A64Pilot 1 Quote
Don.Tulsa Posted January 27, 2022 Report Posted January 27, 2022 A few months back I bought my first Mooney M20E, have not noticed any steering issues until the other day. Just as I reached rotation speed and was about to pull the noise up (no Cross Wind) the plane violently decided to turn left off the runway. I didn't see any damage and the plane lifted off just fine on the next attempt but after I landed, I asked my mechanic to check it out, trouble is he hasn't seen many Mooney's. He reported that there is some slack in the steering but isn't such how to correct it. Any help would be greatly appreciated Quote
Hank Posted January 27, 2022 Report Posted January 27, 2022 How straight was the rollout on landing? Don Maxwell has an excellent article, The 8-Second Ride, about worn bushings in the nose wheel and how to fix them. 1 Quote
Browncbr1 Posted January 27, 2022 Report Posted January 27, 2022 if your main gear discs are old and flat with a sagging tail, it changes the geometry of the nose gear, which causes a shimmy. the nose wheel doesn't have enough trail when the tail sags too much. 1 Quote
KB4 Posted January 27, 2022 Report Posted January 27, 2022 On 10/12/2021 at 10:42 PM, ZuluZulu said: I was taught bottom of the block by a 20-year M20J owner CFI. Dude should have read the POH before teaching you that. 1 Quote
Marauder Posted January 27, 2022 Report Posted January 27, 2022 A few months back I bought my first Mooney M20E, have not noticed any steering issues until the other day. Just as I reached rotation speed and was about to pull the noise up (no Cross Wind) the plane violently decided to turn left off the runway. I didn't see any damage and the plane lifted off just fine on the next attempt but after I landed, I asked my mechanic to check it out, trouble is he hasn't seen many Mooney's. He reported that there is some slack in the steering but isn't such how to correct it. Any help would be greatly appreciatedSounds like some loose bushings. If the mechanic isn’t familiar with Mooney rigging, I’d find someone who is. He should be checking the pre-loads as well as the general condition of the hardware. Sent from my iPhone using Tapatalk Pro Quote
carusoam Posted January 27, 2022 Report Posted January 27, 2022 D.T, What technique did you use? What speed did you use to break ground? 1) Squirreliness isn’t expected… 2) if you wait too long, it will happen… 3) worn Biscuits can exacerbate the issue… 4) worn steering horns are known for this… 5) transition between driving and flying occurs over time and distance… it isn’t a momentary change… 6) if you let it fly off the runway on its own… you have waited too long… 7) if you run off the runway to the left… while raising the nose… this isn’t a steering issue… it’s a torque / rudder issue… +1 for reading the 8-second ride… it is the time for a full ride on the back of a bull… PP thoughts only… -a- Quote
Hank Posted January 27, 2022 Report Posted January 27, 2022 If the OP waited too long to rotate, he could easily have wheelbarrowed with the mains off the ground and only the nose wheel touching. Then any crosswind correction will also steer the plane pretty quick. 2 Quote
Yetti Posted January 28, 2022 Report Posted January 28, 2022 if you go to fast you can get the shimmy. Holding a bit of BACK pressure on the yoke will fix that. Quote
ZuluZulu Posted January 28, 2022 Report Posted January 28, 2022 13 hours ago, KB4 said: Dude should have read the POH before teaching you that. This POH doesn't apply to my plane. Should I still tell him he's wrong? Quote
Guest Posted January 28, 2022 Report Posted January 28, 2022 16 hours ago, KB4 said: Dude should have read the POH before teaching you that. That statement in the PoH is only valid if the trim position indicator is rigged correctly, which many are not. Clarence Quote
Guest Posted January 28, 2022 Report Posted January 28, 2022 18 hours ago, Don.Tulsa said: A few months back I bought my first Mooney M20E, have not noticed any steering issues until the other day. Just as I reached rotation speed and was about to pull the noise up (no Cross Wind) the plane violently decided to turn left off the runway. I didn't see any damage and the plane lifted off just fine on the next attempt but after I landed, I asked my mechanic to check it out, trouble is he hasn't seen many Mooney's. He reported that there is some slack in the steering but isn't such how to correct it. Any help would be greatly appreciated The steering system is not complicated but is subject to wear. There are a number of wear points in the steering, jack the airplane, block the co pilot pedals with a piece of wood and a pair of clamps then carefully wiggle the nose wheel while looking for worn or loose parts. Does your maintainer have manuals for the plane? Shimmy can also be caused by improper nose gear caster angle, Service Bulletin M20-202 covers this. Clarence Quote
Browncbr1 Posted January 28, 2022 Report Posted January 28, 2022 (edited) 3 hours ago, M20Doc said: That statement in the PoH is only valid if the trim position indicator is rigged correctly, which many are not. Clarence that's right!... and not just on the block under the belly...... on my 67F, the indicator needle is so easily bent also... during some interior work on the center console, this is easily bent. the slightest movement of the wire housing can change indications drastically.. also, if trim tube universal joints are removed in order to inspect wear on the guide blocks, an unexperienced technician can reinstall the universal joints 180 degrees or more rotations out of trim. Edited January 28, 2022 by Browncbr1 Quote
KB4 Posted January 28, 2022 Report Posted January 28, 2022 5 hours ago, ZuluZulu said: This POH doesn't apply to my plane. Should I still tell him he's wrong If he gave you that flat advice “always on bottom” yes tell him he is wrong. Or you can tell the manufacturer they are wrong your choice. @ZuluZulu Since this Trim setting doesn’t apply to your J. yours must have different guidance on Trim Settings, show me! I’m very interested to see that, would you please take a pic. What’s different? My bet no pic the trim setting guidance IS exactly the same as yours. Quote
Don.Tulsa Posted January 28, 2022 Report Posted January 28, 2022 4 hours ago, M20Doc said: The steering system is not complicated but is subject to wear. There are a number of wear points in the steering, jack the airplane, block the co pilot pedals with a piece of wood and a pair of clamps then carefully wiggle the nose wheel while looking for worn or loose parts. Does your maintainer have manuals for the plane? Shimmy can also be caused by improper nose gear caster angle, Service Bulletin M20-202 covers this. Clarence I have a short video that shows what we think is slack, would you mind viewing it and letting me know what you think? Quote
Don.Tulsa Posted January 28, 2022 Report Posted January 28, 2022 20 hours ago, Marauder said: Sounds like some loose bushings. If the mechanic isn’t familiar with Mooney rigging, I’d find someone who is. He should be checking the pre-loads as well as the general condition of the hardware. Sent from my iPhone using Tapatalk Pro thank you I agree looking for someone now Quote
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