M20K Rocket - Control Issue

[Jeff H.]

Owned for 35 hours. Always flown straight and level hands off.

Return from service (oil change), first flight, strong left turn in all phases - need 15 - 20 degrees right on control wheel for straight and level flight.

Only other information is that on same flight GAD43 failed (part of G500 install). Left turn tendency exists with autopilot off. Century 41 autopilot.

Absolutely only other item is that it appeared that level trim was slightly nose down compared to past flights - trim indicator was at bottom of center mark.

In flight, ailerons appeared equal, flaps fully up. Where do I start to look? (Other than for a good MSC . . . )

Rookie Rocket owner - I appreciate your patience and knowledge.

[KSMooniac]

Look down the trailing edges of the ailerons and flaps, and see if any of them got mashed.

[philipneeper]

do you have a wing leveler? 

[M016576]

Sounds like the shop that did the oil change might have bumped something into one of your ailerons or flaps. I'd check to make sure the trailing edges of all your control surfaces are flush and not dinged/bent first before anything else. Also, maybe oneof your flaps isn't fully retracted.

[aviatoreb]

Yeah - what he said.

 

Some bent control surface or a bent part of a wing, etc.  Something likely got broken.   Or a asymetrically deployed flap, or did you look at your speed brakes?  Are they both retracted.

 

As part of every preflight, esp when it sits on the ramp, and esp when it gets refilled by someone else, or touched by someone else - I include "did it get hit by a truck" as part of my preflght inspection.

[robert7467]

Also cycle your gear and check the doors. Mine was pulling to the left and it appears that my gear is haning on one side a couple inches lower.

[carusoam]

From the G website....

"The GAD 43 adapter unit offers enhanced autopilot interface capabilities for the G600/G500 flight display systems. It enables AHRS digital attitude/heading reference to be used with selected autopilots in place of costly-to-maintain ADI gyro indicators."

Was it only with the auto pilot on?

Try talking to the person that worked on this device...?

Is it mounted anywhere under the cowl?

Best regards,

-a-

[Marauder]

The GAD43 substitutes for the AI information that you used to get from your Century AI interface. If the AP is disconnected, it should not be involved UNLESS for some reason it is staying engaged or has hung a servo. I would make sure the breakers are all pulled for the AP and even the G500 to make sure that none of it is contributing to the problem.

Robert above mentions the gear hanging. That is a definite possibility.

As well make sure your flaps are okay. Should be visible in flight if the left one is dropping relative to the aileron. And I believe you said everything looks level.

I would also check the security of everything underneath (like the cowl flaps, if installed are moving uniformly).

[Guest]

Perhaps it was over steered with a tug while moving it int o or out of the shop. The nose gear and rudder control inter connect with the aileron is biasing the ailerons to cause the roll problem?

Clarence

[Jeff H.]

All right, I got my list. Thank you very much to everyone for your help. I'll post a follow-up once resolved.

MooneySpace - gotta love this place.

Jeff

[shorrick mk2]

Re - assymetric flap deployment. Are they not driven by a unique torque-rod, which in turn is driven by one motor? Hard to see how one would deploy more than the other...

[BillC]

I had the exact problem on my J. One flap was not fully retracted because of a very small delamination the the lower trailing edge of the wing skin. It was enough to catch on the flap and stop it from retracting the last few degrees. Once on the ground I lifted the flap and heard a small snap. Looking under the wing I could see where a small piece of the lower wing had delaminated causing the flap to stop fully retracting. It was an easy fix. As mentioned, check flaps are fully retracted.

Good luck,

Bill

[FlyWalt]

  On 12/10/2014 at 3:53 AM, Jeff H. said:

MooneySpace - gotta love this place.

Jeff

 

Yes you do. The experience and knowledge that the people have here has saved me many headaches and dollars over the years.

[M016576]

  On 12/11/2014 at 2:21 PM, shorrick mk2 said:

Re - assymetric flap deployment. Are they not driven by a unique torque-rod, which in turn is driven by one motor? Hard to see how one would deploy more than the other...

You are correct- it is a unique torque-rod w/ one motor, but it doesn't take much to bend the connecting rods or impede a single flap. A total split flap situation is pretty unlikely, but a partial split flap scenario has happened before, and Is less unlikely. It doesn't take much of a split to cause a rolling moment- look at how little aileron deflection it takes to start a roll

[Marauder]

  On 12/11/2014 at 2:21 PM, shorrick mk2 said:

Re - assymetric flap deployment. Are they not driven by a unique torque-rod, which in turn is driven by one motor? Hard to see how one would deploy more than the other...

Someone stepped on the flap. A mechanic with the boards can tell if they are correct.

[M016576]

  On 12/12/2014 at 4:38 AM, Marauder said:

Someone stepped on the flap. A mechanic with the boards can tell if they are correct.

Was thinking the same thing.

[DAVIDWH]

Sometimes I think those "Stepping on the flap" oil change guys can be as bad as the "Golf cart riding linemen that

 

over torque the nose wheel."

 

Seems like, same as a baby, we should never let her out of our sight.

[Piloto]

Yeap. It sounds like a sumo wrestler could not reach the black wing walk area and stepped on the flaps. This happens when the boarding step is removed for .001kts speed increase.

 

José

[BillC]

  On 12/9/2014 at 8:10 PM, Jeff H. said:

Owned for 35 hours. Always flown straight and level hands off.

Return from service (oil change), first flight, strong left turn in all phases - need 15 - 20 degrees right on control wheel for straight and level flight.

Only other information is that on same flight GAD43 failed (part of G500 install). Left turn tendency exists with autopilot off. Century 41 autopilot.

Absolutely only other item is that it appeared that level trim was slightly nose down compared to past flights - trim indicator was at bottom of center mark.

In flight, ailerons appeared equal, flaps fully up. Where do I start to look? (Other than for a good MSC . . . )

Rookie Rocket owner - I appreciate your patience and knowledge.

Jeff,

Did you find out what the problem was?