Control Rigging
- Chris in Milwaukee
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Control Rigging
So, since I've had the Maule, it's flown with a bit of a lean to the right and a half bubble off to the left. Having resolved to cure this problem, I took the bird to the shop today, along with the service manual, and turned it over to the mechanics for an inspection. The maintenance director turned it over to an experienced guy, and he set it up just as the instructions in the book dictated, and found some cool stuff.
* Dihedral was good on both sides
* Washout was .2" on the left, .5" on the right
* Aileron travel normal
* Left aileron drooping 3/8"
* Right aileron drooping 1/8" (ailerons should be 0 to -1/4")
* Aileron cable tension about 5-8 lbs low, controls a little sloppy (no yoke deflection with minor control surface movement)
* Flap travel normal
* Left flap drooping 1/8-1/4"
* Right flap normal position
* Rudder travel normal, cable tension normal
* Rudder position normal, rudder springs normal
* Elevator travel normal, cable tension normal
With that in mind, if the left side controls are drooping, then that explains my heavy right wing and being a half bubble off to the left (corrected with right rudder).
Mechanic is going to set cable tension and surface position, and we'll go for a ride and see if that straightens things up. Hoping that helps out before doing bigger stuff, like disconnecting wing struts and such.
Heck, with luck, might even get another MPH or so out of the deal!
* Dihedral was good on both sides
* Washout was .2" on the left, .5" on the right
* Aileron travel normal
* Left aileron drooping 3/8"
* Right aileron drooping 1/8" (ailerons should be 0 to -1/4")
* Aileron cable tension about 5-8 lbs low, controls a little sloppy (no yoke deflection with minor control surface movement)
* Flap travel normal
* Left flap drooping 1/8-1/4"
* Right flap normal position
* Rudder travel normal, cable tension normal
* Rudder position normal, rudder springs normal
* Elevator travel normal, cable tension normal
With that in mind, if the left side controls are drooping, then that explains my heavy right wing and being a half bubble off to the left (corrected with right rudder).
Mechanic is going to set cable tension and surface position, and we'll go for a ride and see if that straightens things up. Hoping that helps out before doing bigger stuff, like disconnecting wing struts and such.
Heck, with luck, might even get another MPH or so out of the deal!
Christopher Owens
1993 MX-7-180A
Members: AOPA EAA VAA
1993 MX-7-180A
Members: AOPA EAA VAA
- gbarrier
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Lean to the right might have been the more washout on that side. Drooping ailerons only mean that the yoke won't sit straight when the ailerons are aligned as they streamline in the wind, at least if they were manufactured straight.
Be sure the flaps are exactly the same angle. There are a lot of them hanging out there. With the wash the same it should trim up pretty straight with the ball near center. Hate to but if it doesn't you might need to tweek a flap a tiny bit.
Be sure the flaps are exactly the same angle. There are a lot of them hanging out there. With the wash the same it should trim up pretty straight with the ball near center. Hate to but if it doesn't you might need to tweek a flap a tiny bit.
- Chris in Milwaukee
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- DeltaRomeo
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- Chris in Milwaukee
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- Chris in Milwaukee
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It does tend to drop the right wing first on stall, so probably another clue.DeltaRomeo wrote:Make the washout the same on both sides; otherwise it will cause an unwanted stall effect...
I did also notice when I was doing a quick geometry measurement that tailpost to wingtip trailing edge corner was about 3/4" off between the left and right sides. But that may not be a trustworthy measurement due to variations in fiberglass parts installation. The measurement would be more accurate if I took the wingtip off.
Not that I could square the structure up, anyway, without removing the fabric and heating longeron tubes to strategically shrink the steel and bring things back into perfect alignment. That's a rebuild/restore operation.
"Perfection is the enemy of completion."
Christopher Owens
1993 MX-7-180A
Members: AOPA EAA VAA
1993 MX-7-180A
Members: AOPA EAA VAA
- Andy Young
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- Chris in Milwaukee
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Oh sure, I get it. No concerns at all. Just an observation. She'll fly like a champion.Andy Young wrote:And you're talking a level of perfection that was likely not achieved at the factory. Not being disparaging here; just the reality with most reasonably-priced light aircraft.
I'm building a Bearhawk and expect the same to be true. Handmade aircraft will always vary a little bit.
Christopher Owens
1993 MX-7-180A
Members: AOPA EAA VAA
1993 MX-7-180A
Members: AOPA EAA VAA
- DeltaRomeo
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- Chris in Milwaukee
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Flew the MX for the first time since it was re-rigged. Heck of a difference! It does barely tend to wander off to the right when hands off, still. But one finger on the yoke and it doesn't move. That's a lot better than it was before when I had to constantly hold the yoke with a fair amount of pressure.
It's still a half ball off under normal conditions, and I have to keep right rudder on to keep it straight. If I have the rudder trim pulled all the way out, it'll stay mostly on center.
I think I'll fly it for a bit and try to get a feel for what it needs. Perhaps, as suggested by others in the archives, I can adjust the tab on the rudder so it's located off to the right a bit at neutral aileron.
I didn't check for speed differences since I was mainly trying to feel for level. But when I was coming back toward the airport, I did notice about 105 MPH at 2200-2300 RPM.
It's still a half ball off under normal conditions, and I have to keep right rudder on to keep it straight. If I have the rudder trim pulled all the way out, it'll stay mostly on center.
I think I'll fly it for a bit and try to get a feel for what it needs. Perhaps, as suggested by others in the archives, I can adjust the tab on the rudder so it's located off to the right a bit at neutral aileron.
I didn't check for speed differences since I was mainly trying to feel for level. But when I was coming back toward the airport, I did notice about 105 MPH at 2200-2300 RPM.
Christopher Owens
1993 MX-7-180A
Members: AOPA EAA VAA
1993 MX-7-180A
Members: AOPA EAA VAA
- Andy Young
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- Andy Young
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