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Aileron Rigging

mark960

Active Member
Is there any way to check the aileron rigging without taking off the wingtips???

My ailerons are about a ?? lower than the flaps which are not fully flush either. It may be normal, but it doesn?t look right. The wingtip screws are painted on and I don't want to mess up the paint.

Mark K
N1075 RV9A



FLAPS Fully Retracted
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LEFT Aileron
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RIGHT Aileron
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Yes there is a way to rig without removing the wingtip

Mark,
I see the pictures of your aileron above. My questions would be how do they look in flight and does the plane fly level without trim?

You have two rod ends for each aileron (one at the aileron and one at the bellcrank in the wing). One full turn of a rod end is worth about 1/16” inch. I adjusted mine to trail with the flaps (at the inflight condition). Additionally, You can adjust them to counteract any heavy wing condition.

NOTE: be certain to comply with any minimum thread requirements as stated by Vans
 
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Flaps are generally in a "reflex" position, meaning they will be a little higher than the ailerons. I believe the goal is to have the flaps up against the rear spar so the flap mechanism is not under load during normal flight. Some prefer to make everything line up, but it is very build specific due to wing mount variations.

The tips should come off at each condition inspection, so the screws shouldn't be a concern. Replace with stainless, IMO.
 
To the OP question, yes you can check aileron rigging without taking off the wingtips.

But, you have multiple issues to be checked and fixed. If you rely on the ?tooling holes? approach to rigging you can easily end up with rigging problems. I?ve seen a lot of RVs not properly rigged. Rigging is not ?one and done?.

Here is one of a few posts I made on rigging: http://www.vansairforce.com/community/showthread.php?t=165907&page=2

For builders not yet there, I again strongly recommend deferring wingtip fit-up until after the wings, flaps and ailerons are mounted and rigged.

Carl
 
It looks like the flaps and the ailerons are mis-rigged, but there can be numerous other things that can cause mis-alignments between wing tips ailerons and flaps and fuselage. One major one is twists in the control surfaces. This can be checked for by measuring the angle of a surface at each end while holding it stationary. If they are not twisted, the measured angle should be the same at both ends.
 
Mark,
I see the pictures of your aileron above. My questions would be how do they look in flight and does the plane fly level without trim?

You have two rod ends for each aileron (one at the aileron and one at the bellcrank in the wing). One full turn of a rod end is worth about 1/16? inch. I adjusted mine to trail with the flaps (at the inflight condition). Additionally, You can adjust them to counteract any heavy wing condition.

NOTE: be certain to comply with any minimum thread requirements as stated by Vans


The ailerons in flight are roughly the same as shown, both below the flaps in level flight. The aircraft does not exhibit any wing heavy condition.

I don't think one aileron being up or down would cause a wing heavy condition. A wing heavy condition would be caused and corrected by adjusting the flap trim.


What's got me started down this road, is I have a friend with another RV9A with same engine, and his aircraft is faster by 5-10 knots. That was confirmed by running both aircraft WOT side by side at multiple altitudes. (I know there are lots of things that could be causing the speed difference. The trim is what I'm focusing on now.)
 
What's got me started down this road, is I have a friend with another RV9A with same engine, and his aircraft is faster by 5-10 knots.

I'm not surprised
As I mentioned it looks like your ailerons and flaps are both miss rigged. This wont necessarily cause a roll trim problem any more than flying around with your flaps partially deployed will.

But, if your ailerons and flaps are both drooped downward it will definitely cause drag and a loss of speed.
 
I have rigged my ailerons with the tooling holes and bellcrank locking plate during initial rigging and checked at last condition inspection and still get a roll to the left in flight. Could I eliminate this roll by adjusting flaps? Thanks in advance.
 
I have rigged my ailerons with the tooling holes and bellcrank locking plate during initial rigging and checked at last condition inspection and still get a roll to the left in flight. Could I eliminate this roll by adjusting flaps? Thanks in advance.


A "heavy wing" is caused by the wings producing a different amount of lift on each side. YES, adjusting the flaps will correct this problem. A single turn of the turnbuckle results in a very noticeable change. My plane would bank and turn to the left with hands off. It took only a half turn to correct it.
 
Thanks Mark I will give this a try and report back. My flaps are not flush either, I set them up with a digital level on initial rigging.
 
I have rigged my ailerons with the tooling holes and bellcrank locking plate during initial rigging and checked at last condition inspection and still get a roll to the left in flight. Could I eliminate this roll by adjusting flaps? Thanks in advance.

Flaps are but one item that can create a heavy wing - but easy to fix. Most overlooked (and fairly common) are low/high/in/out aileron brackets.

Recommend stepping back and spending some time to systematically rig your ship. Here is a post on how: http://www.vansairforce.com/community/showthread.php?t=165907&page=2

Don?t forget the wheel pants and gear leg fairings.

Carl
 
Results

OK, so I adjusted the ailerons up so they are now even with the flaps. Sighting down the top wing surface, they appear to be reflexed by about a half a degree. Flew it this morning and I have picked up 3-5 knots. Not sure of the exact speed increase, but definitely an improvement.
 
Flap and aileron rigging

Flaps should be up against the bottom of fuselage; both the same. Ailerons should line up with flaps with elevators neutral and with a slight upward pull on both ailerons to take slack out... Tips should line up with the ailerons.
Heavy wing correction is another issue and is corrected in other ways, not by trying to raise or lower a flap or ailerons.
 
Flaps first

You really want to get this as accurate as possible. It is amazing that squeezing an aileron an imperceptible amount can make a difference. Imagine misaligned surfaces!!

Generally, get the flaps rigged first. The bottom skin flush against the fuselage. This is a solid baseline. Next the ailerons. Work and adjust the rod end bearing until you have perfect alignment. It may take a half turn at a time.

I like to clamp the aileron to the flap. This makes adjusting the rod ends easy. Adjust until the bolt will go through the rod end and the bell crank. Make sure the stick stay in the same spot!!! Don't forget to tighten the jam nut!!

Finally time to bring the tips into compliance. The alignment holes will generally be pretty close from my experience. Adjust the flanges of the tip to get the alignment correct.

Now work on the aileron to tip gap. Fun with fiberglass!!:eek:
 
You really want to get this as accurate as possible. It is amazing that squeezing an aileron an imperceptible amount can make a difference. Imagine misaligned surfaces!!

Generally, get the flaps rigged first. The bottom skin flush against the fuselage. This is a solid baseline. Next the ailerons. Work and adjust the rod end bearing until you have perfect alignment. It may take a half turn at a time.

I like to clamp the aileron to the flap. This makes adjusting the rod ends easy. Adjust until the bolt will go through the rod end and the bell crank. Make sure the stick stay in the same spot!!! Don't forget to tighten the jam nut!!

Finally time to bring the tips into compliance. The alignment holes will generally be pretty close from my experience. Adjust the flanges of the tip to get the alignment correct.

Now work on the aileron to tip gap. Fun with fiberglass!!:eek:

Good advice (since the photos the OP originally posted indicated that the flaps and the ailerons are mis-rigged), but, this advice is only valid if it has been confirmed that the flaps and ailerons do not have an twist in them.

If they do, aligning all of the ends to each other may not be the best procedure.
 
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