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Does CG and loading cause a wing drop?


NJMac

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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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The next time you go out and fly, try that and pay close attention. Regardless of were the ball is sitting, with the wings level and feet on the floor, watch for heading creep. My plane used to do what you are describing. The person before me had solved it by dropping the flap. Turns out, whole thing was out of rig, but the rudder was the main problem with the roll.

 

Does plane act the same at idle and full power?

 

Next thing to try: with the fuel balanced, accelerate the aircraft in a shallow dive and do about a 2G pull. (Don't do a loop unless you want to ) The airplane should track straight ahead in the pull up.

 

Next: if you're comfortable, bring the plane to a reasonably abrupt stall and see which way it wants to roll. Theoretically, it should stall straight ahead. This will also give you some clues about where to look in the rigging.

 

 

 

 

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I hear so many people say they fixed a wing drop issue by adjusting one flap, If your mechanic wants to do that tell them NO! it is not the proper way to fix wing drop. what it does is change the rigging of your flaps and can cause a change in flight characteristics when flaps are down. 

Brian

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Adjusting the ailerons changes the rigging of the flaps? How's that work? Getting everything to zero takes aileron asymetrys due to construction and damage out of the equation and gives you a base to start with.  Set to zero, do a stall series, see if it flat turns (mine did, dropped a wing quickly in stalls too) land, adjust. Fix heavy wing w*th aileron adjustment. You can drop it half a degree or bend, up to you. I dont bend. Once the wings are steady adjust rudder tab for straight flight. Fly, repeat. Dont adjust ailerons based soly on stall series. Too technique dependent, you're really looking for level flight in cruise. There may be a better way, just relaying what worked for me. 

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27 minutes ago, Pete M said:

Adjusting the ailerons changes the rigging of the flaps? How's that work? Getting everything to zero takes aileron asymetrys due to construction and damage out of the equation and gives you a base to start with.  Set to zero, do a stall series, see if it flat turns (mine did, dropped a wing quickly in stalls too) land, adjust. Fix heavy wing w*th aileron adjustment. You can drop it half a degree or bend, up to you. I dont bend. Once the wings are steady adjust rudder tab for straight flight. Fly, repeat. Dont adjust ailerons based soly on stall series. Too technique dependent, you're really looking for level flight in cruise. There may be a better way, just relaying what worked for me. 

no, adjusting the aileron does not change flap rigging, what people do is adjust the flaps if they have a heavy wing to help compensate instead of actually fixing the problem.

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58 minutes ago, NJMac said:

Truly couldn't say.

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The reason I was asking is that if the plane was damaged in the past and the wings or fuselage got very slightly bent without being corrected, that could cause a roll too.

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The reason I was asking is that if the plane was damaged in the past and the wings or fuselage got very slightly bent without being corrected, that could cause a roll too.
Mechanic that dropped the flap eariler this summer tried to say wings were not symetrical. I didn't see it.

Even if that's the case, we can still get it straight, can't we?

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4 minutes ago, NJMac said:

Mechanic that dropped the flap eariler this summer tried to say wings were not symetrical. I didn't see it.

Even if that's the case, we can still get it straight, can't we?

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yes we can

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"Dropping an aileron" does nothing other than put the system even further out of whack.  The reason for this is that the ailerons simply trail at a point of least resistance for both of them- since they are connected!  You can "drop an aileron" as many times as you like and all it will do during a flight test is change the angle of the yoke.

This is why adjusting a flap slightly to correct a small wing dropping tendency does work because the flaps are fixed and can move independently.

One thing that many folks don't account for is the rudder to aileron interconnect in the belly below the pilot's seat.  My current C dropped a wing because someone had adjusted a bunch of linkages to the point that the ailerons and rudder (and nose wheel steering) were fighting each other through the  2 springs that connect the aileron and rudder pushrods.

My solution, that actually worked:

-I disconnected the interconnect springs, leveled the yokes IAW the maintenance manual (easy to do on Mooneys without wingtips) and straightened out the bent rudder trim tab.

- I put the rudder straight in relation to the nosewheel, adjusted the rod ends and reconnected.

- I moved the interconnect Pushrod attachment point on the aileron pushrod so that all the tensions were as neutral as possible, and reconnected everything else.

-I adjusted the flap stops (not just the outer stops, but the inner linkages as well) to make them even with the ailerons (IAW the maintenance manual).

After test flying, I had to tweak the rudder trim about 1/4" and I adjusted my right flap outer flap stop 1/2 turn.  

My airplane flies straight, hands off, with the ball centered and it stalls straight as well. TAS for my M20C at 75% power is 149 knots.

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1 hour ago, Andy95W said:

"Dropping an aileron" does nothing other than put the system even further out of whack.  The reason for this is that the ailerons simply trail at a point of least resistance for both of them- since they are connected!  You can "drop an aileron" as many times as you like and all it will do during a flight test is change the angle of the yoke.

This is why adjusting a flap slightly to correct a small wing dropping tendency does work because the flaps are fixed and can move independently.

One thing that many folks don't account for is the rudder to aileron interconnect in the belly below the pilot's seat.  My current C dropped a wing because someone had adjusted a bunch of linkages to the point that the ailerons and rudder (and nose wheel steering) were fighting each other through the  2 springs that connect the aileron and rudder pushrods.

My solution, that actually worked:

-I disconnected the interconnect springs, leveled the yokes IAW the maintenance manual (easy to do on Mooneys without wingtips) and straightened out the bent rudder trim tab.

- I put the rudder straight in relation to the nosewheel, adjusted the rod ends and reconnected.

- I moved the interconnect Pushrod attachment point on the aileron pushrod so that all the tensions were as neutral as possible, and reconnected everything else.

-I adjusted the flap stops (not just the outer stops, but the inner linkages as well) to make them even with the ailerons (IAW the maintenance manual).

After test flying, I had to tweak the rudder trim about 1/4" and I adjusted my right flap outer flap stop 1/2 turn.  

My airplane flies straight, hands off, with the ball centered and it stalls straight as well. TAS for my M20C at 75% power is 149 knots.

Andy,

please go back and read the maintenance manual, they specifically address correcting a heavy wing and your procedure does not follow the manual. 

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5 hours ago, Andy95W said:

"Dropping an aileron" does nothing other than put the system even further out of whack.  The reason for this is that the ailerons simply trail at a point of least resistance for both of them- since they are connected!  You can "drop an aileron" as many times as you like and all it will do during a flight test is change the angle of the yoke.

This is why adjusting a flap slightly to correct a small wing dropping tendency does work because the flaps are fixed and can move independently.

One thing that many folks don't account for is the rudder to aileron interconnect in the belly below the pilot's seat.  My current C dropped a wing because someone had adjusted a bunch of linkages to the point that the ailerons and rudder (and nose wheel steering) were fighting each other through the  2 springs that connect the aileron and rudder pushrods.

My solution, that actually worked:

-I disconnected the interconnect springs, leveled the yokes IAW the maintenance manual (easy to do on Mooneys without wingtips) and straightened out the bent rudder trim tab.

- I put the rudder straight in relation to the nosewheel, adjusted the rod ends and reconnected.

- I moved the interconnect Pushrod attachment point on the aileron pushrod so that all the tensions were as neutral as possible, and reconnected everything else.

-I adjusted the flap stops (not just the outer stops, but the inner linkages as well) to make them even with the ailerons (IAW the maintenance manual).

After test flying, I had to tweak the rudder trim about 1/4" and I adjusted my right flap outer flap stop 1/2 turn.  

My airplane flies straight, hands off, with the ball centered and it stalls straight as well. TAS for my M20C at 75% power is 149 knots.

I dont disagree with you but by your theory bending a trailing edge shouldnt work either but it does. You're simply causing one to fly up and the other down. That will also turn the yoke.

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7 minutes ago, Pete M said:

I dont disagree with you but by your theory bending a trailing edge shouldnt work either but it does. You're simply causing one to fly up and the other down. That will also turn the yoke.

it is not a theory. it is the procedure in maintenance manual. if you have a heavy wing, you are already turning the yoke to compensate. when properly rigged the yoke will be neutral with the wings level. 

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6 hours ago, Andy95W said:

"Dropping an aileron" does nothing other than put the system even further out of whack.  The reason for this is that the ailerons simply trail at a point of least resistance for both of them- since they are connected!  You can "drop an aileron" as many times as you like and all it will do during a flight test is change the angle of the yoke.

This is why adjusting a flap slightly to correct a small wing dropping tendency does work because the flaps are fixed and can move independently.

One thing that many folks don't account for is the rudder to aileron interconnect in the belly below the pilot's seat.  My current C dropped a wing because someone had adjusted a bunch of linkages to the point that the ailerons and rudder (and nose wheel steering) were fighting each other through the  2 springs that connect the aileron and rudder pushrods.

My solution, that actually worked:

-I disconnected the interconnect springs, leveled the yokes IAW the maintenance manual (easy to do on Mooneys without wingtips) and straightened out the bent rudder trim tab.

- I put the rudder straight in relation to the nosewheel, adjusted the rod ends and reconnected.

- I moved the interconnect Pushrod attachment point on the aileron pushrod so that all the tensions were as neutral as possible, and reconnected everything else.

-I adjusted the flap stops (not just the outer stops, but the inner linkages as well) to make them even with the ailerons (IAW the maintenance manual).

After test flying, I had to tweak the rudder trim about 1/4" and I adjusted my right flap outer flap stop 1/2 turn.  

My airplane flies straight, hands off, with the ball centered and it stalls straight as well. TAS for my M20C at 75% power is 149 knots.

I dont disagree with you but by your theory bending a trailing edge shouldnt work either but it does. You're simply causing one to fly up and the other down. That will also turn the yoke.

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When you bend it one flys up, the other down, yoke turns...same...same. I had an msc rig them with the boards...no bueno...tried bending...no bueno...zeroing them out fixed the problem. Didnt mess with the rudder interconnect but would have liked to have disabled it. 

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6 hours ago, orionflt said:

Andy,

please go back and read the maintenance manual, they specifically address correcting a heavy wing and your procedure does not follow the manual. 

I've been reading the maintenance manual for about 27 years and own a few copies, some of them digital for different years/models.  I've rigged Mooneys using the rigging boards.  The boards are essential for up/down limit stops and for new installations of pushrods or after significant work.

There are a few additional issues:  the ailerons were changed in 1965, and are the ones shown in the manual.  The 1964 and earlier ones, like mine (picture below) don't have the same effect from bending the trailing edge.  Additionally, over about 50 years, mine have been bent (and probably rebent) by previous A&Ps so I'm not really comfortable bending them more.  Also, the maintenance manual shows bend limits for them.  This is fairly easy to measure on the newer ailerons, less so on the earlier ones (excerpt included below).

Moving a flap stop by 1/2 turn is still within the +/- tolerances shown in the service manual limits.

Correcting a heavy wing per the manual is all well and good if it hasn't been screwed with over 50 years by people who either didn't have the boards or didn't understand what they were doing. 

IMG_1913.PNG

IMG_1915.PNG

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6 hours ago, SheryLoewen said:

Wing heaviness should be adjusted with aileron rigging by properly bending the trailing edge down or straightening if improperly bent previously.

I'd like to start by saying I have the utmost respect for you and your husband and everything you've done for the Mooney community for 50+ years.

My ailerons are the old (pre-1965) style and have been bent and unbent over the past 50 years by previous mechanics who might not have known what they were doing (I'm an A&P myself and admit I'm not perfect and don't know everything).  Setting it up the way I described, then giving a very small adjustment to a flap stop, keeps it within Service Manual limits and kept me from having to bend my ailerons any more than they already are.

Now, if Loewen's Mooney Salvage has any new-style ailerons that I can buy for a reasonable price, I'm all ears!

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46 minutes ago, Pete M said:

I dont disagree with you but by your theory bending a trailing edge shouldnt work either but it does. You're simply causing one to fly up and the other down. That will also turn the yoke.

The reason that it's not quite the same is that bending the trailing edge acts as a servo tab, but only on that one aileron.  The other aileron stays the same, so the net effect over the whole system is to lift the heavy wing.

(Full embarrassing disclosure- when I was a new A&P I thought I could fix my first M20Cs heavy wing by "adjusting" an aileron.  I ended up with an airplane that was catty-wumpus and still had a heavy wing.  The only way I could put it right was to get out the book, borrow the rigging boards, and do it right.)

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The new style ailerons have beveled trailing edges to reduce the hinge moment in order to lighten the control forces. Bending the trailing edge on older style ailerons doesn’t work as well due to the higher hinge moment to overcome. 

Bending the aileron trailing edge is a final operation to correct minor rolling tendencies after all the rigging has been checked per the Service  Manual. It’s very effective - doesn’t take much. If the trailing edges are noticeably bent, the problem is somewhere else and someone has tried to compensate for it by  messing up the ailerons.

Here’s a good article on flight testing rigging:

Shoptalk - rigging.pdf

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Just one more fine detail - a yaw tendency might not be your rudder.  In addition to Bobs retract step add to the list of things to look at your gear doors.  If one is hanging in the breeze it will cause the plane to seem out of rig and land a speed penalty as well. 

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