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Flaperon Alignment Question

M

mturnerb

Well Known Member
I recently purchased an RV-12 S-LSA. I noticed today that when the stick is neutral, the trailing edge of both flaperons sits about 1/4" below where it would be perfectly aligned with the trailing edge of the outer wing. I've had no problems in flight, have not left flaps extended beyond the white arc, and have double-checked that the flap hand is firmly in the up "detent". If i position the stick so that one flaperon is aligned, the other is about 1/2" below the "aligned" position.

Is this the normal neutral position? If not - is it something that is easily adjusted? More importantly, is there any concern about flying? I need to fly Monday - otherwise would pose this question (and will if needed) to Van's when able to reach them.

Thanks in advance.
 
mturnerb said:
I recently purchased an RV-12 S-LSA. I noticed today that when the stick is neutral, the trailing edge of both flaperons sits about 1/4" below where it would be perfectly aligned with the trailing edge of the outer wing. I've had no problems in flight, have not left flaps extended beyond the white arc, and have double-checked that the flap hand is firmly in the up "detent". If i position the stick so that one flaperon is aligned, the other is about 1/2" below the "aligned" position.

Is this the normal neutral position? If not - is it something that is easily adjusted? More importantly, is there any concern about flying? I need to fly Monday - otherwise would pose this question (and will if needed) to Van's when able to reach them.

Thanks in advance.
Click to expand...

This sounds about normal rigging for for the RV-12, as you place 1/8" spacers on top of each flaperon when when setting up rigging...check with Van's, but I'd fly as long as everything feels normal.
 
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Quote from the RV-12 PAP Manual page G2-2
Place flap handle in "retracted" position and have a helper hold the left flaperon trailing edge in line with tip trailing edge in trail position.
Verify right flaperon trailing edge is 1/4 inch to 1/2 inch below trail position.
Click to expand...
There are several more tests and checks outlined in the PAP if you want to get familiar with the plane and to make sure that everything is right.
 
Thanks Ric and Joe. Sounds like all is well.

I have all the documentation but wasn't able to quickly find that information - will review now that I have a reference.

TB
 
mturnerb said:
I recently purchased an RV-12 S-LSA. I noticed today that when the stick is neutral, the trailing edge of both flaperons sits about 1/4" below where it would be perfectly aligned with the trailing edge of the outer wing. I've had no problems in flight, have not left flaps extended beyond the white arc, and have double-checked that the flap hand is firmly in the up "detent". If i position the stick so that one flaperon is aligned, the other is about 1/2" below the "aligned" position.

Is this the normal neutral position? If not - is it something that is easily adjusted? More importantly, is there any concern about flying? I need to fly Monday - otherwise would pose this question (and will if needed) to Van's when able to reach them.

Thanks in advance.
Click to expand...

Turner,

I also have an SLSA and we spoke a while back when you were contemplating buying your airplane.

I too noticed the fact that the flaperons 'drooped' (for want of a better word) slightly on both sides in cruise with 'flaps up'. This was the way it was rigged when I took delivery from Vans in OR last July.
I inadvertently discovered that if you push the flap button in again you can get them aligned (i.e.. fully flush) by just pushing down on the handle all the way to the floor. I noticed this on my first couple of legs. I would press the flap handle and push it all the way to the floor and it would stay flush with the trailing edge. Other times I'd look out and see the slight droop and thought I'd left the flaps at the first position but they were actually at 'flaps up.'
However, even though they usually stay there I also discovered that they can occasionally pop back down that tiny amount back to the 'flaps up' setting and you might hear a 'clunk' sound as it does so, not every time. Nothing changed in regards to the airplane's handling other than a slight trim change but the clunk did get my attention the first time!

I haven't seen the PAP before so that was an interesting link. So now I'm left wondering is a slight dropping 'normal' and if so what's the reason? The POH doesn't address this as I recall.

BTW If you push the button in and push the handle all the way down to get them flush you can also feel a very slight change in trim.

This has been my experience, hope it helps.
 
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Top Cat said:
Turner,

I also have an SLSA and we spoke a while back when you were contemplating buying your airplane.

I too noticed the fact that the flaperons 'drooped' (for want of a better word) slightly on both sides in cruise with 'flaps up'. This was the way it was rigged when I took delivery from vans in OR last July.
I discovered that if you push the flap button in again you can get them aligned by just pushing down on the handle all the way to the floor.
However, even though they usually stay there I also discovered that they can occasionally pop back up that tiny amount back to the 'flaps up' setting and you might hear a 'clunk' sound as it does so, not every time. Nothing changed in regards to the airplane's handling but it did get my attention the first time!

If you push the button in and push the handle all the way down to get them flush you can also feel a very slight change in trim.

This has been my experience, hope it helps.
Click to expand...

Thanks Howard. I noticed this on the ground, so I'll check in out in the air also. The flap handle is a bit finicky as many have noticed. It's tricky getting it firmly in the retracted position when climbing out after takeoff - I have pinched my thumb about 5 times already (drew blood once). Too bad we can't do a mod on the S-LSA as some others have described.

Turner B
 
Turner?I too have the 'flap handle scar' on my right hand!!

Only 'real RV-12 guys' have that mark!:D

Yes?the E-SLA guys can do the mod which looks very good. Perhaps Vans will include this as an option in the future as it makes sense!
 
From the link to the old post, quoted above, :-

"This is compensated by adjusting each to be drooped very slightly... in flight, the elasticity allows them to be in trail at the proper neutral orientation to the wing."

So does this mean the air load on a drooping/trailing flaperon should be enough to raise it to 'neutral' ( as in aligned with the wing)?

If so, does pushing in the flap button and pushing the flap handle to the floor, which also aligns the flaperons with the wing surface (no droop/trail) actually accomplish the same thing?

Or, does this cause the air load under the wing to push the flaperon upwards, and if it's flush (not trailing) put undue load on the flaperon?

In cruise I've never seen the flaperons on my plane sit flush unless I push the flap handle button and push the handle down to the floor.

I'm asking because my annual is due next month and this maybe something that needs addressing?

I found that this has been discussed before on this forum:-

http://www.vansairforce.com/community/showthread.php?t=112110

http://www.vansairforce.com/community/showthread.php?t=118900&highlight=drooping+flaperons
 
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Sorry, Van's will have answer those questions. My only info is that the rigging instructions on page 32-10 of the Kit Assembly Instructions use two 1/8" shims on each flaperon to droop both ailerons 1/4", the PAP quote back in the 3rd post tests to ensure that was done and the post in the link explains why it's done.
 
Top Cat said:
In cruise I've never seen the flaperons on my plane sit flush unless I push the flap handle button and push the handle down to the floor.
Click to expand...

The optimal droop (on the ground) for most RV-12's is about an 1/8" on each flapperon, which should make them pretty close to in trail in flight (will vary slightly depending on how close to gross weight, etc).
The specified tolerance is rather large since it is not that critical, and making adjustments requires making half turn increments on the rod ends.

In simple terms... as close to 1/8" droop is best, but over slightly is better than under.
 
rvbuilder2002 said:
The optimal droop (on the ground) for most RV-12's is about an 1/8" on each flapperon, which should make them pretty close to in trail in flight (will vary slightly depending on how close to gross weight, etc).
The specified tolerance is rather large since it is not that critical, and making adjustments requires making half turn increments on the rod ends.

In simple terms... as close to 1/8" droop is best, but over slightly is better than under.
Click to expand...

Mine is a bit more than 1/8" - more like 1/4" but this is consistent with what I read in the "PAP" which has one flaperon 1/4" to 1/2" low with the other neutral.

Thanks for all the replies.
 
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