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Old 03-26-2018, 10:56 AM
Greg Bradley Greg Bradley is offline
Join Date: Mar 2018
Location: Paradise, Missouri
Posts: 2
Default Estate RV-12 flaperon issue.

Hello all,

I need some advice or help...

My good friend, RV-12 builder, Doc Ireland passed this winter and left his RV-12 in his estate. I have flown it and found that with flaps down the right flaperon is deflected more like 5 degrees with the 2nd notch of flaps. Aircraft banks right when flaps are lowered.

I have read some historical comments here and considered all cures to this problem but want to eliminate the easiest first and continue until fixed by an A and P mechanic.

This aircraft has the servo'd autopilot and was first wondering if any linkages from the servos to the control could need adjusting?

I noticed too, that statically, when I put in one or two notches or flaps with stick centered, as flaps are engaged, the control stick moves a unit to the left for each detent. Is that normal?

Thank you.
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Old 03-26-2018, 12:02 PM
Join Date: Nov 2007
Location: Jesup, Iowa
Posts: 1,587
Default Some experience with these issues - -

I would start with taking the rear floor tunnel covers off. ( yes, may be lots of work if tank has to be removed ). I worked on one that had been set up completely wrong. If you have the builder manual, lock the controls as instructed, and go from there. The flaperons should be equal at that point. If not, follow the instructions in the build manual.

ALSO - check the AP servo linkages. They may be off also. Off, as in dangerous.
John Bender
Flying RV-12 - Serial #120036
Paid in May ( 5-4-18 )
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Old 03-26-2018, 12:34 PM
Azjulian Azjulian is offline
Join Date: Dec 2015
Location: Scottsdale, Arizona
Posts: 131

Everything John said + remove the seats and the seat inspection panels and measure all he rods that are built in section 32 - flight controls
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Old 03-26-2018, 01:07 PM
rvbuilder2002 rvbuilder2002 is offline
Join Date: Jul 2005
Location: Hubbard Oregon
Posts: 7,605

I agree with John as well.

I suspect that if you first look at the control horn arms on the inboard end of the flaperons, you will find that they are not exactly aligned with each other when the ailerons are neutral.
Any opinions expressed in this message are my own and not necessarily those of my employer.

Scott McDaniels
Hubbard, Oregon
RV-6A (aka "Junkyard Special ")
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Old 03-26-2018, 01:26 PM
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DaleB DaleB is offline
Join Date: Sep 2012
Location: Omaha, NE (KMLE)
Posts: 1,845

It does sound as though there may be an assembly and/or rigging issue. I'd follow the advice given. Pull the floor panels and inspect. Lock the controls per the assembly instructions, and see if the pushrods are the correct length and the flaperon torque arms and torque tubes are installed and drilled correctly. It's in section 32 of the assembly manual.

On the one I bought, they are not. The plane flies straight and everything works, but one pushrod bumps against the fuel pump at full aileron deflection. Just enough to feel the "bump". We'll be fixing that.
Omaha, NE
RV-12 # 222 N980KM "Screamin' Canary" (bought flying)
Fisher Celebrity (under construction)
Previous RV-7 project (sold)
-=VAF=- 2017 dues paid
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Old 03-26-2018, 07:13 PM
DaveLS DaveLS is offline
Join Date: Oct 2007
Location: Pensacola, FL & 2R4
Posts: 191

The distance between the left and right stick grips does slightly change with flap position.
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Old 03-27-2018, 12:20 AM
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Gagarin737 Gagarin737 is online now
Join Date: Mar 2009
Location: Netherlands
Posts: 632

Due to the geometry of the aileron/flaperon mixer the sticks move somewhat during flap extension/retraction. From what I remember the sticks come together when you pull flaps (you don't notice during actual flight). So if you hold the left stick in a fixed position during flap extension the right flaperon will drop more than the left. If you hold the right stick the left flaperon will drop more.

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Old 03-27-2018, 09:58 PM
Greg Bradley Greg Bradley is offline
Join Date: Mar 2018
Location: Paradise, Missouri
Posts: 2
Default flaperons

Thank you all. I will look at these items as I begin.
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