Control Rigging

[gbarrier]

Tighten up the right rudder spring in the back an inch or two at the time till it flies ball centered with trim about mid position. Chances are you'll just put a little pressure on one or the other rudder as needed after that and hardly adjust it. If its still a tad right wing heavy you might wash that right rear strut in about half turn. Be sure it still stalls straight. If not put it back and perhaps just a tad (like 1/4 turn on pushrod) down on right flap.

They're all different.

[Chris in Milwaukee]

Thanks for the tips. Will give it a go!

[DeltaRomeo]

The rudder trim cable can be repositioned in its clamp (found behind the right kick panel) to provide more tension if you are unable to get the ball centered. You'll find that this trim adjustment changes as fuel burns off in long Xcountry cruises.

[MauleWacko]

[Chris in Milwaukee]

As suggested, I'll be checking the rudder springs (once I find where they are) in the back and making adjustments as needed to fix the yaw problem.

Also as suggested, I'll see about adjusting the washout a smidge and then doing a stall test (before, it dropped a right wing fairly readily). Then following up with a slight flap adjustment after that if it's not desirable.

[DeltaRomeo]

There is no rudder trim on a maule. It is just a way to lock the rudder pedal in a position. If you have to hold any input during flight it is out of rig.

Then I suppose Maule designed all models out of rig and to compensate every aircraft from the factory comes with one of these?

[Andy Young]

There is no rudder trim on a maule. It is just a way to lock the rudder pedal in a position. I never used mine. I removed to whole thing and threw it in a box.
If you have to hold any input during flight it is out of rig. A short fuselage with a long wing span will always hunt and have adverse yaw, funky pitch with cg changes etc.

I'm a little confused by this assertion. Do you mean that since there is no trim tab, there is no true rudder trim? Cessna's rudder trim also works by applying pressure to the pedal, vs. using a trim tab. Does that mean that they also do not have rudder trim, despite the wheel under the panel that says "Rudder Trim"?
Also, are you suggesting that a properly rigged airplane will never need a rudder input to fly coordinated, even in a steep climb or descent? Seems to me that a plane can only be rigged for hands-off straight coordinated flight in one flight regime (usually straight and level); all other regimes will require trim. Indeed, the primary use for rudder trim is to compensate for varying amounts of rudder input needed during climb vs. cruise vs. descent. The mechanism in the Maule that pulls on the right rudder pedal works great for that, if set up and used properly.
One can denigrate the unsophisticated nature of this system, or appreciate the fact that they managed to build a functional system that is much simpler and lighter than others.
Of course, one can always choose to apply correct rudder input entirely with muscle power, and many aircraft have no other option. Since my Maule does have a trim system, I like to use it, especially for long climbs.

[maules.com]

It seems about once a year the rigging comes up.
It is pointless chasing a rig problem without starting from scratch.
Yes, you can fix a situation but at the expense of drag from the next situation.

1. Level the plane laterally using wing root carry through tube behind top of windshield, and by jacking the gear.
2. Check that the tailplane hinge line matches laterally.
3. Run a stringline from inboard edge of composite wing tips and check it is level laterally.
4. Adjust front wing struts to achieve level lateral stringline, and a 3" gap above wingspar roots.
5. Adjust rear struts to achieve the washout in each wing, 1/2 degree trailing edge up at outboard rib.
6. Check the vertical stabilizer is 90 degrees to the elevator hinge line which you have leveled by checking and if necessary changing tail struts.
7. Run a stringline from top of rudder and vertical stab when faired and the line should extend to a point 1 3/4" to left of centre of wing root carry through tube.(This combats left turning tendency in cruise).
8. Adjust the elevators so that the balance portion is equal and flush with stabilizers at BOTH sides otherwise it will roll the plane.
9. Place light upward hand pressure on flap trailing edge and adjust with pushrod until faired correctly with bottom of wing.
Check Both ends of each flap.
Do Not use wing root fairing for reference.
10. Tie a stick across bottom of both control yokes catching four points.
Adjust with turnbuckles.
11. Using above headliner turnbuckles adjust ailerons individually until flush with bottom of wing, checking at both ends of aileron.
IF any of flaps and ailerons is not close to flush with wing bottom at BOTH ends, there is a twisted control surface and the correct rigging will be compromised.
12. Adjust rudder trim bungee so that the spring is slack with T handle fully in (this is for right turn tendency in descent) and light tension on spring when T handle is at one and a half marks on shaft showing.
13. Adjust tail steering springs correctly with a little slack or they will affect the rudder trim.
14. Adjust the rudder servo tab flush with rudder when ailerons are locked together with the stick.
15. Be sure that with no load on either the tailwheel or the nose wheel, the swivel is not too sticky otherwise the wheel will act as a rudder.
It can be kicked loose to go in trail when in flight prior to setting rudder trim.
16. Adjust the rudder centering springs (not on M4 and M5) to be no shorter than 4.5" and to hold the rudder centered when no load on the tail.

Only now can you test fly the rigging as you will be starting from square One, and fine adjustments can be done for roll or yaw.

All the above is in your Maule Maintenance Manual

[Andy Young]

There is no rudder trim on a maule. It is just a way to lock the rudder pedal in a position. I never used mine. I removed to whole thing and threw it in a box.
If you have to hold any input during flight it is out of rig. A short fuselage with a long wing span will always hunt and have adverse yaw, funky pitch with cg changes etc.

I'm a little confused by this assertion. Do you mean that since there is no trim tab, there is no true rudder trim? Cessna's rudder trim also works by applying pressure to the pedal, vs. using a trim tab. Does that mean that they also do not have rudder trim, despite the wheel under the panel that says "Rudder Trim"?
Also, are you suggesting that a properly rigged airplane will never need a rudder input to fly coordinated, even in a steep climb or descent? Seems to me that a plane can only be rigged for hands-off straight coordinated flight in one flight regime (usually straight and level); all other regimes will require trim. Indeed, the primary use for rudder trim is to compensate for varying amounts of rudder input needed during climb vs. cruise vs. descent. The mechanism in the Maule that pulls on the right rudder pedal works great for that, if set up and used properly.

[CaseyM]

HUGE THANK YOU Jeremy!! I'm fighting this same problem (roll to the right) except my T&B is 1/4 ball off to the right. I have the rigging PDF from Duane (Thanks Duane!) and will be addressing this very soon. information and knowledge is key when it comes to these type of things and both of these definitely help. Hopefully it'll help save my wallet from excessive labor time at the MX facility.

[maules.com]

Very often the ball of T&B appears 1/4 ball to right.
With a headset on, because the 6pack is offset to the left one cannot get a straight on view of the ball between the two lines. Parallax.
Another check is to laterally level the plane then check the lateral level of the instrument in the panel. They can be off rotationally.

[CaseyM]

Very often the ball of T&B appears 1/4 ball to right.
With a headset on, because the 6pack is offset to the left one cannot get a straight on view of the ball between the two lines. Parallax.
Another check is to laterally level the plane then check the lateral level of the instrument in the panel. They can be off rotationally.

Good advice! thank you. I'll have them check the gauge that way and verify accurate reading. The roll to the right is my big concern. My MX7 is IFR certified so I need as much straight and level help as I can get.

[Chris in Milwaukee]

Yours and mine act exactly the same, roll, ball, and all. We (service pros) went through the manual and followed the steps to keep from "chasing it", as Jeremy described it. It flies a *lot* better now.

Now, as Jeremy said, I'm at the fly-it-and-tweak-it stage. Very happy with the progress made!

I wanted to share the experience of re-rigging my plane in hopes it would start a conversation from those who may also be experiencing similar problems. Looks like it worked. Couple that with archive posts and you've got yourself a good knowledge base.

~Chris

[Chris in Milwaukee]

Just to close the loop on this adventure, I received the invoice for my re-rigging adventure and it cost one full AMU for the job. Something else to think of when it comes time.

A friend of mine said to me this morning, "Oh yeah, I forgot, you're still new to this ownership game! Everything is 1000! You'll start to go numb after a few more 1000s."

[maules.com]

Ouch, it must've had problems.
Some of those $$ will be returned via mpg, vibration and wear n tear of controls muscle and mind.