Hanging Flaps and Ailerons

[rodsmith]

I have 2004 vintage quick build wings. I'm finally getting around to installing flaps and ailerons. I have found that the closest I can mount them to the rear spar ends up with a chord length of 66 3/8. That leaves the gap between the aileron nose and lower wing skin just 1/8th inch. I could move the trailing edge slightly forward, but probably only an 1/8 inch. I have never heard a discussion of this issue, don't think it is a big problem just curious if others have found the same thing. I plan on building my own wingtips so the extra length won't be a problem there.

[Mark Goldberg]

1/8" is kind of a minimal gap considering fabric on the aileron nose will take up a little of that space.. You could space the ailerons & flap back a little more with AN970 washers under the weldments that attach them to the rear spar. You could put some shims/spacers under the aileron/flap hinges where they mount to the front face of the spars. Or you could trim back the trailing edge of the lower skin a little. Those are all possible solutions that will help. You do not need much more space. Mark

[rodsmith]

1/8" is kind of a minimal gap considering fabric on the aileron nose will take up a little of that space.. You could space the ailerons & flap back a little more with AN970 washers under the weldments that attach them to the rear spar. You could put some shims/spacers under the aileron/flap hinges where they mount to the front face of the spars. Or you could trim back the trailing edge of the lower skin a little. Those are all possible solutions that will help. You do not need much more space. Mark

I hadn't drilled anything yet, so just spaced the flaps and ailerons back another 1/8". That makes a wing chord of 66 1/2". Just curious on how the kit wings end up a 1/2" wider than the plans show.

[rodsmith]

I installed the hinges on one aileron. Now I find that I can't install the an4-12 hinge bolts because the aileron pocket isn't wide enough. Going to have the same issue with 2 of the 3 flap hinges. An an4-11 might be adequate but that doesn't quite fit either. I need to drill a 1/2" hole in the nose rib to move the bolt head into so I can align and install it. I have a right angle drill but the biggest bit I have is 1/4" and I can't find any threaded 1/2" bit. Any ideas? Certainly I am not the only one to run into this.

[Mark Goldberg]

The hinges are off set out of the center so you have room on one side to get the bolt in and out. You should be able to make that work as many others have Rod. Mark

[rodsmith]

The hinges are off set out of the center so you have room on one side to get the bolt in and out. You should be able to make that work as many others have Rod. Mark

Very slightly offset, not enough to get the bolt in. I have the aileron and flap positioned laterally on the wing so there are equal gaps everywhere.

[svyolo]

Would it work if you loosened all the bolts simultaneously, moved the whole flap laterally a bit, and then remove all 3 bolts?

[rodsmith]

Once the hinges are in place there is no lateral movement possible on the aileron or flap. I see what I need to do. Will post more after I correct it so others don't make the same mistake.

[svyolo]

Thought about it again. Yeah can't move it.

[rodsmith]

Wanted to write this up for others who haven't mounted the controls on the original Bearhawk wing. I have no idea if any of this applies to the "B" wing. I know the flaps are longer and the hinges use different bearings. To insert all the hinge bolts in the flaps and ailerons I had to move both inboard from where I had originally positioned them. I was following the quick build wing instructions to position them with equal gaps at the wing tip, between flap and aileron and between flap and inboard portion of wing. I eye balled the spacing in the pockets and thought the bolts would fit but hadn't actually measured them. I also had ordered AN4-12 bolts based on grip length. Turns out you need to use AN4-11 bolts which are just a bit shy (about 2 threads) on grip length. I now have more of a gap at the wing tip and the inboard flap gap is pretty tight. There really is very little error in how you position the controls and still get the bolts in. I also need to trim the bottom wing skin at the outboard end of the flap. With the aileron positioned as far outboard as possible it is virtually touching the skin, so need to trim it back (see picture). I'm anxious to get this completed so I can cover the flaps and ailerons. That is the last fabric work left for me.

[svyolo]

The last couple of days fitted the wingtip, tip rib, aileron pocket skin, made up formers to hang the ailerons and flaps, and hung the ailerons and flaps, fitted -3 nut plates to the ailerons.

Thanks to a couple of threads, it went pretty smooth. I was able to drill all the aileron hinge bolts with the hinges clamped in place. I just rotated the ailerons a bit to access the holes. I was only able to do that to the two upper hinge bolts per hinge.

A few gotchas;

1. The upper wing profile is the most accurate at the tip, root, and where the upper wings skins have overlaps. I would try to use those places to place the wing formers.
2. Offset the hinges in the pockets like stated above.
3. You need to get a countersink/drill/squeezer/rivet gun into the hinge pocket. Make sure you orient the nut plates so you can do those 3 or 4 things. I used about half 1 legged nut plate angle away from the ribs to give enough room.

I was able to use a pneumatic squeezer, on a few of the rivets I had to remove the U-joint on the bottom, and usually had to insert the squeezer from one side, and attach the air hose from the opposite side, but it did work. If you have to drill a rivet out, you might need a 12 inch bit.

I was pretty happy with how it all worked out, but the 8 nut plates on the ailerons took quite a while.

[Gerhard Rieger]

The whole process is time consuming, I have all that done and dusted, busy with the flap and aileron trailing edges.