Proper aileron rigging

[Bennett]

In level flight my M20J tracks true, with no tendency to drop a wing, or turn, but I note that both ailerons are about 3-4 degrees higher at their inboard ends than the flaps, or one could say both the flaps are about 3-4 degrees lower than the inboard ends of the ailerons.  What is the proper rigging?  I hate to fool much with having them adjsuted, unless there is really something wrong with the current setup.  My prior aircraft had the ability to reflex the flaps up almost 10 degrees in level flight, and I did pick up a couple of knots by doing so, (just like the designer said it would). I never heard of reflexing ailerons upwards, and I am curious what the effect would be.  I believe that the Columbia 400 (now Cessna ...400) can reflex her flaps upwards to gain speed in level flight.

Any aerodynamists on the forum that would venture an opinion? 

[kerry]

If I remember right I believe the pre-J ailerons are set at 2 degrees downward from flaps.  I would think the J would be the same.

[Parker_Woodruff]

Quote: kerry

If I remember right I believe the pre-J ailerons are set at 2 degrees downward from flaps.  I would think the J would be the same.

[Kwixdraw]

Might be a good time for a thorough inspection of the flap hinges and bellcrank. The hinge mounts get corrosion in them and the flaps sometimes get damaged by people stepping on the right one entering and exiting the aircraft. The jack screw is on the left side of the fuselage and when the right flap gets stepped on there is a lot of torque being applied to the bellcrank and operating mechanism. I might not be so concerned if the flaps are even right to left. lower them slightly and look for equal deflection from centerline under the tail.  Check for unequal play in them too.

[Magnum]

The ailerons can be rigged from 0 to -2 degrees (flush with the flaps or pointing down). Due to some play in the system they will be slightly up in flight if they are rigged to 0 degrees. I rigged mine to -2 degrees and in flight they are flush.

To do it correctly (and make sure the flaps are set correct) you need the travel boards. I tried it with a protractor, it is doable, but much easier with the boards.

[jetdriven]

 Book spec is ailerons from 0 degrees to -2 degrees.  

[1964-M20E]

I just finished my annual and rigged all of the control surfaces and if I remember correctly I set the ailerons at -1 and the flaps at 0.  My first annual and I wanted to verify the rigging and I changed some rod ends as well.  If you and your mechanic are comfortable with doing the rigging you will need the travel boards and the maintenance manual for your plane it will have all the instructions, settings and travel limits.  You can rent the travel boards from the hangartoolbox.com Tim is great over there.  It is not difficult just tedious some of the rod ends are a PIA (pain in the ass) to get to.  The elevator was the most interesting of the bunch to set.  The other alternative is to bring it to Dugoush or Don Maxwell I have never used either of them for work on my plane but the feedback about them is excellent.

[John Pleisse]

Kerrie McCintyre wrote the best MAPA article ever on rigging. It's a great read. He details quantity of aileron droop. The rigging service instruction details this too. Sorry, I don't have it in front of me, but for a "J" I recall it being -1 or -2, flaps 0. Also, aileron rod ends that are not adjusted or wearing can create some play as well.

[Bennett]

Thanks to everyone who replied.  It would seem that my ailerons are set too high, and I will have the good folks at LASAR re-rig them at the next annual.  When I had the airplane repainted a few months ago all control surfaces were removed to be painted separately, and perhaps there was some changes made in re-installation, although I noted the "high" ailerons before painting. I know LASAR has the templates, tools, and expertise to do the re-rigging. The airplane is in such good trim, I almost hate to have any work done on them. 

[JaredDavis]

Do you know what issue has the rigging article?

[John Pleisse]

Quote: JaredDavis

Do you know what issue has the rigging article?

[takair]

Quote: Bennett

Thanks to everyone who replied.  It would seem that my ailerons are set too high, and I will have the good folks at LASAR re-rig them at the next annual.  When I had the airplane repainted a few months ago all control surfaces were removed to be painted separately, and perhaps there was some changes made in re-installation, although I noted the "high" ailerons before painting. I know LASAR has the templates, tools, and expertise to do the re-rigging. The airplane is in such good trim, I almost hate to have any work done on them. 

[Bennett]

Jim, Yes, your photograph of your ailerons in flight match my sight view.  I am ever more of the opinion I will not change the rigging as the airplane trims hands off so perfectly.  

When the airplane was being painted at ArtCraft in Santa Maria ( really great people to work with) a couple of months ago, I asked them if they knewa good chrome shop as I wanted a few interior hardware pieces chrome plated - door handle and four strap end pieces.  While we were at it, we added the pitot tube.  While I don't recall the exact price, I think the total came to about $75.00.  I also had the prop spinner polished out, and as much as I wanted to have it chrome plated, there was sufficient talk on the various forums to convince me it wasn't a good idea.  

[Clarence]

Jim and Bennett,

If your left and right ailerons are riding high equally in level cruise flight, lowering both the same amount will not change the flying qualities of the airplane other than reducing drag.  In the picture you can see that the mass balance at the tip is quite lower dropping into the slip stream below the wing causing drag.

Roll correction or changing the rigging is done by trailing edge bending on the aileron.  If the wing flap up limit stop bolt is set corredtly with the travel board the ailerons should be even with the flap trailing edge in cruise.  If they are not you are flying on a different airfoil than Mooney built.  This can be costing you several knots at the high end, just as the ball being off center as little as a 1/4 ball costs a few knots.

When I have to adjust the aileron or flap trailing edge I don't use the 3" wide vice grip pliers as suggested in the manual.  I've seen many ailerons with wavey trailing edges.  I use 2 pine 1X2 boards clamped on the trailing edge with "C" clamps.  This allows you to bend the entire trailing edge a very small amount over the entire trailing edge with no waves.

Most of the Mooneys I have worked on and flown require fine tuning of flight controls to get them flying straight, fast and efficient.

Clarence

 

 

 

[Bennett]

Clarence, Thanks for the information.  At next annual at LASAR I will ask them to make the adjustments.

[Clarence]

Hi Jim,

If the flaps are correct as checked with the travel boards, I would check the droop of the ailerons with the control wheels locked.  I would set them to 1.5 to 2 degrees drooped.  You are correct that you have to adjust the rod end bearing at the aileron. 

With the wheels locked, the aileron bellcranks in the belly and the wings have specific postions to be set, once those are correct you can set the droop with the aileron rod ends.  Depending on which version you have there may be 2 adjustable bearings or just the forward one. The entire proceedure is in the manual.  Although not required in the US, in Canada we require two AME's (A&P's) to inspect and sign off the system for correct safetying of check nuts cotter pins etc.

Once these steps are completed, go fly the plane in smooth air, the ailerons should be even with the flaps, if not re adjust the airons until they match.  After that adjust the trailing edge to correct roll and yaw with the rudder tab or trailing edge.  The maual only allows bending of aileron trailing edges down, never up and only a very limited amount.

Good luck,

Clarence

 

 

[fantom]

Quote: JimR

 

[TLSDriver]

I have sort of the opposite issue.  When in straight and level flight and the ball in the center the plane wants to turn to the right.  

It takes a fair amount of force on the yolk to keep it from dropping a wing.

Do I need to take this to a specialized shop or can a local A+P to work on this?

Thanks

 

[fantom]

Quote: TLSDriver

When in straight and level flight and the ball in the center the plane wants to turn to the right.  

Do I need to take this to a specialized shop or can a local A+P to work on this?

 

 

You must have a conservative plane

While your friendly Cezzzna A&P can work on it, you'll get better results from a Mooney guru.

[TLSDriver]

Quote: fantom

[fantom]

Quote: TLSDriver

[Parker_Woodruff]

Quote: TLSDriver

[TLSDriver]

What are\is the Mooney travel boards?

[KSMooniac]

The travel boards are Mooney tools that fit over the wing (or tail) and are used to determine or set the travel and rigging of the control surfaces.  Have a look here:  http://www.hangartoolbox.com/Pages/19.aspx   Any adjustments done without these tools are just shots in the dark and could make the rigging worse instead of better.  

[TLSDriver]

Is this a trial and error process or will a good tech put it on these boards and have the plane flying straight again?