Floating ailerons

[markejackson02]

When my plane is on the ground, I can align one aileron trailing edge with the flap and the other one also lines up.  I understand due to the nature of the push rod linkages there is a small amount of "play" between the two ailerons, but it is very small.  Hold one in place and the other can move maybe 1/4".

 

In flight, the ailerons look way out of alignment, as much as an inch, usually the right will be high with the left aligned with the flap.

 

I am at a loss as to how this occurs.  Any thoughts?

 

 

[carusoam]

Watch the relationship of fuel tanks and people?

The ailerons appear to be holding up the heavy side.

In smooth air the plane can be so well balanced that you can turn left and right by leaning from pilot side to passenger side...

If it drifts to one side or the other, burn fuel from the side that is heaviest.

I ran this experiment using a 45 year old C using a portable Garmin with LCD display...

Pretty amazing old plane...,

-a-

[N201MKTurbo]

The ailerons produce lift, so they both are pushed up during flight. This takes all the play out of the aileron system. This is how we can control the bank of the plane with no play or backlash. If one is high in flight with the wings level you need to adjust your flap stops to get them to be equal. Your flaps are like giant ailerons.

 

You can rig a Moooney to fly perfectly straight hands off with one aileron high, but it will go faster and look better if it is rigged correctly.

[N33GG]

The ailerons produce lift, so they both are pushed up during flight. This takes all the play out of the aileron system. This is how we can control the bank of the plane with no play or backlash. If one is high in flight with the wings level you need to adjust your flap stops to get them to be equal. Your flaps are like giant ailerons.

 

You can rig a Moooney to fly perfectly straight hands off with one aileron high, but it will go faster and look better if it is rigged correctly.

 

+1 Good words!

[cliffy]

You didn't say if you were holding ailerons in a slight turn to hold straight and level. What happens when you are in cruise and you are hands off of the wheel? Will it hold straight and level? If it doesn't you have a rigging problem.

Start by having your mechanic go through the rigging procedure in the MM to get everything "near" correct. Then fly and see what happens. I had to do several flights with small movements of the flap stops and rudder trim tab to get things done. Then I looked at the ailerons and they were both up some. I then shortened the control rods equally on them until they were in perfect trail with the flaps AND the counter balance horn being perfectly lined up fair with the wing (IN FLIGHT)and the plane flew hands off level and straight.

[Alan Fox]

Don't adjust the flaps to correct for ailerons , Have it done correctly with the travel boards....If it is indeed out of rig , You will be glad you did it right , Also as Anthony stated Fuel and payload will affect aileron position in flight.....  Your aileron trim is that Big yoke thingy in the cockpit!!!!

[markejackson02]

Flying hands off usually results in a pitch digression before the plane starts turning.  I will trim everything out and try to test it more precisely this weekend.  The plane is due to be painted in about a month so I anticipate we will have to re-rig and rebalance everything then anyway.

[jhbehrens]

My S flies right aileron up and left aileron flush with flaps when in straight and level flight with the ball centred. We have gone through the entire MM rigging procedure, checked all flight controls with rigging boards and all appears fine. Als replaced a whole bunch of rod ends that looked like they had excessive play. But still, when I go fly, the yoke is tilted ca 10 deg right and the right aileron is about an inch higher than the flaps at the trailing edge.

 

The only thing we can still think of doing is bending the trailing edge as per the MM procedure.

 

If anyone has any other ideas about what could cause this I would be very interested.

[Guest]

Flight control rigging is not too hard. Locate and replace all worn and sloppy rod end bearings.

All are essentially the same, lock the two yokes together with a straight edge across the control wheels.

Adjust the lower center bell crank under the floor with the off set per the manual or install the rig pin per the manual.

Adjust the left and right wing bell cranks per the manual by use of the wing push rod.

Adjust the left and right aileron short rods from the bell crank to the aileron for up to two degrees of droop in the static position, generally more droop for faster planes.

Adjust the left and right flap up stop bolts to zero degrees as measured with the correct travel board.

Test fly the plane. You should end up with aileron and flap trailing edges aligned at cruise speed with the ball centred. If not you will have to make small adjustments.

I never bend the aileron trailing edges with wide vice grips as shown in the manual. I use two long boards clamped to the trailing edge with many clamps so I end up bending the entire edge a very small amount and never end up with waves caused by vice grips.

Clarence

[N201MKTurbo]

Replacing rod ends is a waste of money, it will not fix anything.

Adjusting the rods will only affect the yoke position and aileron height.

If they are unequal you have to bend the trailing edges or adjust the flap stops.

You can get it perfect without the travel boards, it just takes a little longer.

[Guest]

How do you set correct neutral position without travel boards?

Clarence

[N201MKTurbo]

I use an inclinometer and equalize the angel difference between the top surface of the wing just in front of the aileron and the top surface of the aileron and the bottom surface of the wing and the bottom of the aileron.

I find mooney wings and ailerons are all just a little different.

You can also lay a straight edge on the top and bottom of the wing and split the difference to get the zero degree position.

Having the boards save a lot of hassle, but very few people have them.

If they were all made perfect we could just align the counterbalances and call that the neutral position.

Anyway, it is hard to find the position they will have in flight. On the ground the aileron system is unloaded and even with two people holding the two ailerons there is a few degrees of play. Even if you clamp the yokes to a straight edge you can move the ailerons a few degrees, so where do you set the position? It should be at the top of the slop.

My point is that no mater how accurate you are you need to make some final tweaks after observing them in flight.

[jhbehrens]

Flight control rigging is not too hard. Locate and replace all worn and sloppy rod end bearings.

All are essentially the same, lock the two yokes together with a straight edge across the control wheels.

Adjust the lower center bell crank under the floor with the off set per the manual or install the rig pin per the manual.

Adjust the left and right wing bell cranks per the manual by use of the wing push rod.

Adjust the left and right aileron short rods from the bell crank to the aileron for up to two degrees of droop in the static position, generally more droop for faster planes.

Adjust the left and right flap up stop bolts to zero degrees as measured with the correct travel board.

Test fly the plane. You should end up with aileron and flap trailing edges aligned at cruise speed with the ball centred. If not you will have to make small adjustments.

I never bend the aileron trailing edges with wide vice grips as shown in the manual. I use two long boards clamped to the trailing edge with many clamps so I end up bending the entire edge a very small amount and never end up with waves caused by vice grips.

Clarence

 

Hi Clarence

 

I have done all that, bought the travel boards (no one in the Netherlands had them), replaced a whole bunch of rod ends and it had zero effect. My right aileron is still up - about 1 inch I'm guessing - when I fly straight & level with left flush.

 

Will take on board your bending technique.

 

Jorgen

[N201MKTurbo]

I would adjust the flap stops first before you bend the ailerons. Turn the right one in 1/2 turn and the left one out 1/2 turn and see what happens. both methods work, but with the flap stops, you can always undo it. Bending is a bit severe.

[N33GG]

Friends don't let friends bend airplanes!!!