Does CG and loading cause a wing drop?

[NJMac]

Ever since I've owned my E, the right wing has been heavy. Drops pretty quickly if I go hands off and most times I'm not able to maintain heading with rudder alone.

 

I had a local mx look at it, he dropped a flap and it got slightly better.

 

I also paid a MSC to re rig the plane and was disapointed to find minimal appreciable differences.

 

As I'm solo flying the plane back from MSC, seat in forward flying position, the right wing still drops. Legs get tired and i want to stretch so i slide seat all the way back and the wing drops noticeably less.

 

Any scientific reason for any of this?

 

Should rigging make it dead straight no matter what? I want it hands free straight and level but never have had that yet. Should I keep working towards that?

 

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[N201MKTurbo]

You can make it fly level hands free.

You can’t fix a heavy wing with travel boards on the ground. 

You need to adjust it, fly it, then adjust it some more until it is right.

you want to get it so it not only flys level but also stalls level.

Too bad you are so far away, we could have a day of plane tweaking.

[1964-M20E]

What year is your E?

If I remember reading correctly there was a point in the manufacture of the M20 where the tail was actually twisted because of we on the jig used during fabrication.  It is not noticeable when looking at one plane but if you looks a a number of them lined up is it visible.  This may have seem effect on the rigging.

Like Turbo said you have to play with it.

Years ago my mechanic and I rigged my E according to the manual and it flew well.

[NJMac]

You can make it fly level hands free.
You can’t fix a heavy wing with travel boards on the ground. 
You need to adjust it, fly it, then adjust it some more until it is right.
you want to get it so it not only flys level but also stalls level.
Too bad you are so far away, we could have a day of plane tweaking.

When I pulled up on my plane on flight tracking while they were supposedly rigging it, they only did one flight in the pattern and I really thought that was odd.

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[NJMac]

What year is your E?
If I remember reading correctly there was a point in the manufacture of the M20 where the tail was actually twisted because of we on the jig used during fabrication.  It is not noticeable when looking at one plane but if you looks a a number of them lined up is it visible.  This may have seem effect on the rigging.
Like Turbo said you have to play with it.
Years ago my mechanic and I rigged my E according to the manual and it flew well.

I've seen some places call it a 1963 and other places it's called a 1964.

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[Bob_Belville]

You may know that your plane was built in late 1963 but it is #132 of 366 1964 M20Es. There's no such thing as a 1963 E. Think model year as with automobiles: http://www.mooneyevents.com/chrono.htm (The date showing on the government data base is not correct.) But you probably know that.

Random thoughts on rigging:

• Did the MSC use the Mooney rigging boards to adjust the flaps, ailerons, and rudder? That's just step one.
• From there tweaking really requires a certain amount of experience and test flying. These planes were hand built. 
• Does your step retract completely? Hand crank? 
• Wing drop can be speed sensitive. (And possible CG sensitive as you seem to be experiencing.)  
• If the problem is the ailerons or the flaps you might get it to stay level with the rudder but you don't want to do that. It ain't elegant and it will cause drag. 

[NJMac]

 

 

 

You may know that your plane was built in late 1963 but it is #132 of 366 1964 M20Es. There's no such thing as a 1963 E. Think model year as with automobiles: http://www.mooneyevents.com/chrono.htm (The date showing on the government data base is not correct.) But you probably know that.

Random thoughts on rigging:

• Did the MSC use the Mooney rigging boards to adjust the flaps, ailerons, and rudder? That's just step one.
• From there tweaking really requires a certain amount of experience and test flying. These planes were hand built. 
• Does your step retract completely? Hand crank? 
• Wing drop can be speed sensitive. (And possible CG sensitive as you seem to be experiencing.)  
• If the problem is the ailerons or the flaps you might get it to stay level with the rudder but you don't want to do that. It ain't elegant and it will cause drag. 

 

My step is a hand crank and I haven't lowered it in all but the first flight that I took. I guess I assumed it was fully retracted but I'll go double check the next time I go flying.

 

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[Bob_Belville]

11 minutes ago, bluehighwayflyer said:

I have never read or heard of Mooneys built with twisted tails.  @1964-M20E, if you can provide more info on this I’d be very interested in reading it.  Thank you.  Also, @Bob_Belville, as you know, having recently transitioned from a J to a C , I am still learning the vintage systems.  Is it noticeable in flight if the step fails to retract, either in the form of speed decrease or yaw? Thank you, too.

Jim

Jim, the later fixed steps are designed to be aerodynamic but the retracting step is a big fat square tube. If it is hanging out is is a big drag, maybe 5 kts or a little more. I suppose the drag is slightly asymmetric but you might not be able to feel it. 

I speak from experience. When I picked up my plane after my new panel was installed my friend filmed the departure. When I watched it I realized that the step was hanging out. That explained why this E was slower that 943RW.

 

[Bob_Belville]

1 minute ago, bluehighwayflyer said:

What did you determine to be the cause of your step failing to retract, Bob?  Just curious.  

Jim

I knew immediately to look at the "servo", a rubber boot that uses vacuum to pull and hold up the step. These boots seem to have a useful life of about 50 years. (There is a thread or 2 on MS because the only company, Brittain Industries, that provided the servos had difficulties with the mold for the rubber part and then the death of the owner/inventor/engineer.) 

[Bob - S50]

Thinking out loud.  Combining all the above.

If the tail is truly twisted just a bit, it could be the horizontal stabilizer that is causing the roll.  At aft CG, there is less down force required from the horizontal stabilizer so there would be less rolling tendency.  Or if the elevators were mis-rigged (if such a thing is possible), more force from one side than the other would also cause rolling which would also be minimized during aft CG loadings.

[NJMac]

I calculated my E the other day to be doing 152 kts TAS with its 3 bladed prop. It's not a slow plane. It still surprises me how quickly it wants to rotate on the takeoff roll and how it just keeps accelerating in the air.

 

What's the group's suggested next steps for 59X? Take it somewhere? Have the local mx look at x, y, or z? Sell it cheap and get an ovation - you'll have to pitch it to my wife.

 

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[skydvrboy]

3 hours ago, NJMac said:

Ever since I've owned my E, the right wing has been heavy. Drops pretty quickly if I go hands off and most times I'm not able to maintain heading with rudder alone.

I had this exact same problem with my F.  It flew pretty decent, but during my first annual the A&P noticed the rigging was out of spec, so he broke out the travel boards and rigged the flaps, rudder, and elevator to spec.  After that, the wing drop was really bad.  He "fixed" it by dropping a flap and it flew slightly better.  Before you start "fixing" it, you need to know if they ailerons or the rudder are the problem.   With your feet on the floor, hold the plane level with the yoke, if the ball is centered your tail and rudder are fine.  Repeat with using just the rudder pedals, if the ball is centered, your tail/rudder is the problem.

At Oshkosh I talked to Don Maxwell about this and he said he sees this commonly with A&P's who are used to working on other planes.  My rudder was fine and only the ailerons were off, so he offered me the following advice:

First, put the flap back where it belongs.  Fixing this with the flap adds a lot of drag and does little to stop the roll (that whole moment arm thing).

Second, check the ailerons with the yoke level and see if one is higher than the other, if so, get them level. (That fixed my problem, so I stopped there.)

Third, bend the trailing edge of the aileron on the "heavy" wing up slightly.  This will act like a trim tab and push the aileron down raising that wing.  A tiny bit of bend goes a long way, fly, rinse, repeat, until it flies straight.

If the rudder/tail are out of alignment, I can't offer you any advice... other than call DMax and see what he recommends.  Oh, your step has virtually no bearing on this.  I've flown with mine up and down and can't tell the difference other than it flying a lot slower (again, that whole moment arm thing).

[NJMac]

I had this exact same problem with my F.  It flew pretty decent, but during my first annual the A&P noticed the rigging was out of spec, so he broke out the travel boards and rigged the flaps, rudder, and elevator to spec.  After that, the wing drop was really bad.  He "fixed" it by dropping a flap and it flew slightly better.  Before you start "fixing" it, you need to know if they ailerons or the rudder are the problem.   With your feet on the floor, hold the plane level with the yoke, if the ball is centered your tail and rudder are fine.  Repeat with using just the rudder pedals, if the ball is centered, your tail/rudder is the problem.
At Oshkosh I talked to Don Maxwell about this and he said he sees this commonly with A&P's who are used to working on other planes.  My rudder was fine and only the ailerons were off, so he offered me the following advice:
First, put the flap back where it belongs.  Fixing this with the flap adds a lot of drag and does little to stop the roll (that whole moment arm thing).
Second, check the ailerons with the yoke level and see if one is higher than the other, if so, get them level. (That fixed my problem, so I stopped there.)
Third, bend the trailing edge of the aileron on the "heavy" wing up slightly.  This will act like a trim tab and push the aileron down raising that wing.  A tiny bit of bend goes a long way, fly, rinse, repeat, until it flies straight.
If the rudder/tail are out of alignment, I can't offer you any advice... other than call DMax and see what he recommends.  Oh, your step has virtually no bearing on this.  I've flown with mine up and down and can't tell the difference other than it flying a lot slower (again, that whole moment arm thing).

Thank you for this starting point.

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[DXB]

I've been there- a heavy wing is very annoying, really messes with your hand flying in the clouds too.  The pertinent advice has  already been given above.  There is a trial and error component, so it has to go into the air after each adjustment.  All MSCs are not equal in their abilities as I'm sure you've noticed.  In case you happen to spend time in the Northeast, Airmods in Robbinsville NJ is outstanding at the rigging stuff.  They got mine flawless in about 2 hrs of work - it will put a smile on your face the first time you fly it without the roll tendency.

[NJMac]

I've been there- a heavy wing is very annoying, really messes with your hand flying in the clouds too.  The pertinent advice has  already been given above.  There is a trial and error component, so it has to go into the air after each adjustment.  All MSCs are not equal in their abilities as I'm sure you've noticed.  In case you happen to spend time in the Northeast, Airmods in Robbinsville NJ is outstanding at the rigging stuff.  They got mine flawless in about 2 hrs of work - it will put a smile on your face the first time you fly it without the roll tendency.

I talked with them and almost had them re-rig it. Will totally be worth the flight once its fixed. I paid 2 hrs labor for my "rigging".

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[carusoam]

When you have it rigged really well...

Still expect the wings to drop, one side or the other, based on cabin loading and fuel level...

My 65C was able to follow a black ‘magenta line’ in Smooth air... black magenta line = LCD G186...

 

I tried on one flight to see how well balanced its rigging was... it did incredibly well, hands off, using weight shifting, by the pilot while the other three people were sleeping.... 

turning to the left is hard... The pilot’s head runs into the window...

Cg related,  

• Side to side... yes.
• front to back... no.

Nobody usualy discusses lateral Cg very often... rudder trim is used for lifting heavy wings... when the rigging is properly set...

Best regards,

-a-

[orionflt]

Bring it to Qtown we will get it tweaked

Brian

[skydvrboy]

It’s one thing to have wing drop that happens only after 10 seconds or so and can be corrected with rudder input.  I don’t think that is what the OP is talking about though.  He mentioned he can’t stop it with the rudder. That seems more like what I was experiencing, 20 degree or more of roll per second when letting go.

Now that it’s fixed , I’ll still get a wing to drop with no control inputs, but loading determines which one and all can be stopped with rudder input.

[NJMac]

It’s one thing to have wing drop that happens only after 10 seconds or so and can be corrected with rudder input.  I don’t think that is what the OP is talking about though.  He mentioned he can’t stop it with the rudder. That seems more like what I was experiencing, 20 degree or more of roll per second when letting go.
Now that it’s fixed , I’ll still get a wing to drop with no control inputs, but loading determines which one and all can be stopped with rudder input.

That's correct. The drop is significant and immediate. I don't go hands off since I don't like how quickly it happens.

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[Guitarmaster]

Ever since I've owned my E, the right wing has been heavy. Drops pretty quickly if I go hands off and most times I'm not able to maintain heading with rudder alone.
 
I had a local mx look at it, he dropped a flap and it got slightly better.
 
I also paid a MSC to re rig the plane and was disapointed to find minimal appreciable differences.
 
As I'm solo flying the plane back from MSC, seat in forward flying position, the right wing still drops. Legs get tired and i want to stretch so i slide seat all the way back and the wing drops noticeably less.
 
Any scientific reason for any of this?
 
Should rigging make it dead straight no matter what? I want it hands free straight and level but never have had that yet. Should I keep working towards that?
 
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Does it act the same with the PC on and off?

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[NJMac]

Does it act the same with the PC on and off?

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It wss removed, no longer on the plane. Looking at a new autopilot this year so want this wing drop resolved before I move on that.

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[Pete M]

I had the same problem with a 64e. Ser 418. No pc. I tied a broomstick across the yoke and used a bubble level that measures angle at the approprate rivet line. See svc manual. Limits were 0-2dg down. Set to 0. I think i referenced to the angle of the wing. Set flaps to be out of the relative wind. Set rudder tab to center ball in cruise. Airplane flew straight and 163tas after that.  Dont recall if i had to set one aileron down a bit after that. Dont think so. Old flat ailerons. I tried the bending trailing edge thing with less than steller results.

[NJMac]

I had the same problem with a 64e. Ser 418. No pc. I tied a broomstick across the yoke and used a bubble level that measures angle at the approprate rivet line. See svc manual. Limits were 0-2dg down. Set to 0. I think i referenced to the angle of the wing. Set flaps to be out of the relative wind. Set rudder tab to center ball in cruise. Airplane flew straight and 163tas after that.  Dont recall if i had to set one aileron down a bit after that. Dont think so. Old flat ailerons. I tried the bending trailing edge thing with less than steller results.

This one has the curved airlerons. Went out for an instrument lesson this morning. Yoke holding straight and level and the ball is not even half a ball width to the left. What's that tell us?  

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[Guitarmaster]

It wss removed, no longer on the plane. Looking at a new autopilot this year so want this wing drop resolved before I move on that.

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Ok. If you hold the wings level, and leave your feet on the floor, does the airplane want to flat turn?

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[NJMac]

Ok. If you hold the wings level, and leave your feet on the floor, does the airplane want to flat turn?

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I don't think so. It will hold a straight course with the airlerons but the ball is less than a half width to the left.

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