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1979 Pa-18 150 Aileron rigging

skyhauk80q

Registered User
Shevlin
Need some help with aileron rigging on a 1979 Pa-18 150. The left aileron was out of rig. Was drooping down about an inch. Can get both ailerons level but do not get full down travel on left aileron. Full travel is 18 degrees up and down right? Reason for aileron droop to begin with was cable was ran under wing strut near cabin instead of on top. I have only turn the turnbuckles on left side. Do i need to adjust right side? Any help anyone? Or someone i could call? Thanks
 
Stops are under the rear stick and on the center aileron hinge. Adjust those for full travel which I would have to look up in the Type Certificate Data sheet because my brain has turned to Luscombe mush today. Rig each aileron turnbuckle and the center balance cable over the pilot's head, fly and then see what you have. The airplane could have been rigged to fly straight with the miss routed cable and you will have to rerig the wings to fly straight. I hope that is not the case.
 
Bear with me.

You'll have to bear with me here first super cub worked on so not to familiar with them. So if i am understanding you right when i get the ailerons level i can control the amount of travel by the stops? It apparently must be hitting the stop on the stick because its not hitting the stop under the wing. Now by moving this stop wont it also cause the right aileron to have a greater up travel?
 
OK! Some of you real mechanics check my methods here. :roll:

Rig the wings per the factory specs. (do a search on here for information as it has been discussed thoroughly).

Loosen the aileron cable turnbuckles at the ailerons evenly. The TOP turnbuckles are the cable that goes to the bottom of the control stick. The BOTTOM turnbuckles are the balance cable that crosses at the top of the cabin.

Center the control stick and hold centered (bungee?). Center the ailerons (large spring clamp on the trailing edge).

Evenly tighten the control cables to XX lbs. of cable tension.

The PRIMARY stops for aileron travel are at the bottom of the stick. The stops out on the center aileron hinge are SECONDARY stops.

Set aileron travel with the stops at the bottom of the rear stick, then slide the secondary stops to touch the aileron horns at full travel. The secondary stops are held in place with a sheet metal screw into the center hinge arm.

How'd I do?

John Scott
 
great job.

Keep all the comments a coming. Wont get to work on it until this weekend but reading all that is posted. Thanks
 
Steve Pierce said:
There is a bolt with a stop nut on either side so one doesn't effect the other.


farther you droop the left aileron, the farther the right one will go up . ( if you are adjusting the stop under the stick.)
(at least I think that was what he was asking)
 
aileron droop

Yeah that's what i thought, that if i adjusted that nut it will also make the right aileron travel farther up. The right one has the correct travel its the left one that needs to travel farther down. So am i understanding it right that if i adjust the nut it will also make the right one travel farther?
 
lets see if i got this right?

If i have this right get the aileron so it is level when the stick is centered, and then adjust the nut to gain full down travel of left aileron? Is the travel indeed 18 degrees?
 
Prior to Dan's Aircraft "shortened flap handle" mod, we used to rig the stick 1 1/2" off center (to the right) to allow more aileron travel with the flap handle up in cross wind landings (Ak Peninsula technique).

I flew one like this for years and liked it a lot better then a centered stick. At rebuild I shortened the flap handle and re-centered the stick (an even better set up).

Take care.

Crash
 
Longwinglover said:
OK! Some of you real mechanics check my methods here. :roll:
......................
Loosen the aileron cable turnbuckles at the ailerons evenly. The TOP turnbuckles are the cable that goes to the bottom of the control stick. The BOTTOM turnbuckles are the balance cable that crosses at the top of the cabin.

Center the control stick and hold centered (bungee?). Center the ailerons (large spring clamp on the trailing edge).

*********Evenly tighten the control cables to XX lbs. of cable tension.

The PRIMARY stops for aileron travel are at the bottom of the stick. The stops out on the center aileron hinge are SECONDARY stops.

Set aileron travel with the stops at the bottom of the rear stick, then slide the secondary stops to touch the aileron horns at full travel. The secondary stops are held in place with a sheet metal screw into the center hinge arm.

How'd I do?

John Scott


pretty good...


0. move stops at stick bottom and wing so they will not interfere for now if needed
1. loosen cables
2 center stick, or offset to right/your "center" position like crash talked about above
3 tighten TOP cables only! till ailerons are UP 1/2" above where they should end up when done.
4 tighten bottom cable(s) (they are just a carry through, they are just like one hooked up between the two bottom points) to get the right tension and bring ailerons down to the right position(flat to bottom of wing).
5 recheck stick and such
6 set the stops at bottom of stick first to get the required travel (18 deg......legally)
7 then set the wind stops(on the center aileron hinge) .. the only purpose these have is to keep the wind from rolling the aileron around and/or hurting things when blown from behind.
8 safety turn buckles ect.

mike
 
Yeah - when you say 18 deg legally, do you mean the same thing as flaps at 50 deg legally?

I flew an aircraft out of Alaska with a flaps 60 setting, and I was suitably impressed!

I have also flown a modified Super Cub with ailerons that simply lose effect in the stall. I am still thinking about that one. I realize that the rudder is primary in the stall, but a normal stock Cub does have some aileron authority right after touchdown - not so this one.
 
Hi i've just discovered this forum thread and wondered if someone may be able to help? I'm struggling to get my 1944 L4 Cub to fly straight hands off!
Its in with maintenance now and I was flight testing some changes that were made yesterday.

Late last year we noticed that the aircraft had developed an apparently new tendency to roll left when hands off (with the stick moving left of neutral). After further investigation it was noted that
in order to fly straight and level with the ball centred, constant right stick force (but only very slightly right of centre) was required resulting in, contrary to logic, right aileron down float and left aileron up float. This was not apparent on the ground in the hangar with both ailerons neutral for that same stick position. Inflight the ailerons and stick naturally float to these off centre, left rolling, positions.

Maintenance suggested that before we adjust ailerons we make sure the aircraft is flying straight. Thus the rear struts (wash out) on both wings have been adjusted such that, when the aircraft is flying straight and in balance, the left and right ailerons are now neutral. The stick position is very slightly(1/2inch) right of centre which isn’t the end of the world. The wing dihedral has been checked and is symettretical. We are therefore satisfied that the aircraft now flies straight and true with the ailerons in their neutral position. Progress!



However (here’s the but...), inflight, the aileron positions still tend to a ‘left turning’ deflection. This has remained the same both prior and post the strut adjustments. Ie inflight, hands off, the ailerons deflect to roll the aircraft left. Right stick force is needed to prevent this still.

I wonder if anyone else has come across this or may be able to offer some advice on what adjustments need to be made?
My UK maintenance organisation is scratching their head as much as I am!

Thanks in advance!
Cubkiter
 
Step one. Make sure the ball is telling you the truth. Do that by putting plane level side to side using a level under WINGS about at jury struts and getting equal number side to side. Ball should be centered now. If not rotate gauge till ball is centered. (Also fuselage should be level Sid to side at this point if you followed the rigging instructions). Then go fly with ball in center, you care not what it does if ball is not centered


Sent from my iPhone using SuperCub.Org
 
kind of uncommon but I have run into it twice. If the ailerons deflect in flight the two I have worked on the ailerons were acting like a big trim tab. One of them had a trailing Edge deflected down. like I said it is unusual but ailerons are supposed to Trail evenly in flight. Good luck
 
I had the same problem on two different aircraft. In one case I even un-riveted an aileron, put it in a jig, and re-riveted it with proper wash. Did not help.

One of the airplanes was a CC 180 Cub that had wing damage, and one aileron was replaced. Those ailerons and that stupidly heavy aircraft are long gone.

Yes, I did try a trim tab. It was never enough.

Finally, after about ten years of wondering (the offending ailerons remaining here were stored) I took the ailerons to the workbench and did some moderately precision measurements.

Long story even longer: one aileron had the hinge centerlines lower than the other. I think it wasn't much - maybe a sixteenth of an inch - but if you think about it, those hinges are critical on a Frieze (sp?) aileron.
 
I don't know if this will help anybody but for those trying to rig their ailerons with the stick centered, you can loosen up the rear caps on the torque tube enough to get a strip of aluminum in between the cap and the torque tube. Then clamp it back down and your stick should remain stationary
 
I finally fixed the 180 CC by swapping ailerons with the trainer J-3. Flew fine after that. The J-3 is a pattern trainer, so nobody noticed. Swapped them back when the heavy Cub left town.

My personal Cub got fixed with a different set of ailerons. The offending ailerons are hanging from the hangar rafters. To fix the bad ailerons one would need a new spar and really good jigs.

I feel kind of dumb - I screwed around with rigging for about six months before I looked out the window and watched the ailerons.

A properly rigged Cub should fly straight and level with only trim and rudder, and the ailerons should be faired equally with the trailing edges. Not opinion. Fact.
 
Thanks for the reply Bob I wasn't quite sure how you solved the problem from your previous post. The Cub I got a hold of was also a cub Crafters 180 horse cub. I ran across it in New Holstein it belonged to a good friend to many here. It was Paul Fisher's airplane may he rest in peace. When I got a hold of it it was a full 6° off Wing to Wing on wash to try and correct the problem. It also had trim tabs all over it to try and get it to fly right from the factory. It is hard to counteract and 8-foot trim tab with an 8 inch trim tab LOL. The hinges were out of line on the ailerons so I bent those in to place with no change. That was after I completely rigged the airplane. It flew great after that on takeoff and Landing but any increasing AirSpeed would take a lot of stick pressure to keep it level. For those of you who didn't know Paul he could be a real pain in the ass LOL. He refused to believe it was his aileron. David Jaranson who we all miss dearly also, offered to swap ailerons for him with his that he knew were good. Paul was adamant that his ailerons were good. I can't recall what we did to get him home or if he just flew with that stick pressure all the way but I doubt that. When he got home another member who I also can't recall loaned him his ailerons and it flew perfect. That was the first time I had ever run into this problem and it really had me scratching my head. It was also the beginning of a long fun friendship with Paul. Anyway thanks for reading my long post anytime I get to put Paul and David in a post I enjoy it a lot.
Love new Holstein great times!

One more thing, univair was great and replaced his aileron no charge
 
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Cubkiter, did someone bump into one of your aileron trailing edges?

that could make the trailing edge act like a trim tab and force the ailerons to "fair" or " trail" uncentered.

......like Ak pa/18 said
 
Thanks for the reply Bob I wasn't quite sure how you solved the problem from your previous post. The Cub I got a hold of was also a cub Crafters 180 horse cub. I ran across it in New Holstein it belonged to a good friend to many here. It was Paul Fisher's airplane may he rest in peace. When I got a hold of it it was a full 6° off Wing to Wing on wash to try and correct the problem. It also had trim tabs all over it to try and get it to fly right from the factory. It is hard to counteract and 8-foot trim tab with an 8 inch trim tab LOL. The hinges were out of line on the ailerons so I bent those in to place with no change. That was after I completely rigged the airplane. It flew great after that on takeoff and Landing but any increasing AirSpeed would take a lot of stick pressure to keep it level. For those of you who didn't know Paul he could be a real pain in the ass LOL. He refused to believe it was his aileron. David Jaranson who we all miss dearly also, offered to swap ailerons for him with his that he knew were good. Paul was adamant that his ailerons were good. I can't recall what we did to get him home or if he just flew with that stick pressure all the way but I doubt that. When he got home another member who I also can't recall loaned him his ailerons and it flew perfect. That was the first time I had ever run into this problem and it really had me scratching my head. It was also the beginning of a long fun friendship with Paul. Anyway thanks for reading my long post anytime I get to put Paul and David in a post I enjoy it a lot.
Love new Holstein great times!

One more thing, univair was great and replaced his aileron no charge

sooooooo...... what was the "problem" with the ailerons??? still trying to wrap my head around the concept...
 
Mike - the hinge line is below the bottom surface of the aileron. Any slight mismatch between ailerons puts tremendous aerodynamic force on the system. A standard size trim tab would be powerless.

Another way of putting it - the slipstream tries to force the aileron down. The same slipstream will act with more force if the aileron is farther above the hinge line.
 
Mike - the hinge line is below the bottom surface of the aileron. Any slight mismatch between ailerons puts tremendous aerodynamic force on the system. A standard size trim tab would be powerless.

Another way of putting it - the slipstream tries to force the aileron down. The same slipstream will act with more force if the aileron is farther above the hinge line.

Hmmm ... looking more for an explanation like... because the left/right? Aileron was above/ below the ?? It causes? This To happen.. and to correct it you must make this right...


Sent from my iPhone using SuperCub.Org mobile app
 
Mike I wish I had more info for you. Paul's airplane had an aileron on that was concave on the lower surface with the trailing Edge canted down. it was a very slight difference you had to look hard. I always assumed that was the issue as that was the aileron that got replaced and the direction of travel made sense. So myself I never fixed anything. It was just replaced. The other cub was beat to hell to begin with and got tore down for a rebuild. So to know 100% that that was the problem I have no way of telling you.
 
Mike I wish I had more info for you. Paul's airplane had an aileron on that was concave on the lower surface with the trailing Edge canted down. it was a very slight difference you had to look hard. I always assumed that was the issue as that was the aileron that got replaced and the direction of travel made sense. So myself I never fixed anything. It was just replaced. The other cub was beat to hell to begin with and got tore down for a rebuild. So to know 100% that that was the problem I have no way of telling you.

hmmm... concave bottom == nose of aileron was down in level position, scooping up air sending it threw the gap to top....????
 
have seen this problem on U206 seaplane rudders.

Rudder gets reskinned and aft skin has a slight "hump" on one side and concave on the other side.

The rudder doesnt fair neutral in flight. It is deflected away from the concave side and yaw trim system cannot overcome it. RESKIN trailing edge!!! and all is well.
 
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