Aileron & Flap Assembly

Photos

Flap Assembly

Here we have the flap with the skin in place. The tie-down straps make the job of wrapping the leading edge skin around the ribs smoothly easier.

Assembly of the flap continues and our QA inspector checks it out!

One step required when preparing the parts for the flaps & ailerons is drilling various sized holes centered on the corner tooling holes, an alternative to the method called for in the MAM manual is to drill the hole with a large drill in a drill press.

A slick way to drill the hole is to clamp the ribs between wood blocks and drill the rib material along with the wood block. If this is attempted without the blocks there is a high risk that the thin rib material will be caught in the drill bit and torn or mangled. You may want to start with a smaller drill for the first pass.

Bushings for the flaps and ailerons must be drilled and countersunk for flat head rivets, drilling brass is a bit tricker than aluminum or steel. The normally ground drill bit "bites" into the material too agressively and makes it hard to do a good job, "dressing" the cutting edge with a honing stone as shown changes the cutting angle making the job much easier. The nose (included) angle of a normal drill bit is fine for the countersunk rivets.

In this view you can see the narrow cutting edge of the drill bit after it has been dressed to drill brass and the bushing after being drilled and countersunk. It helps to use the depth stop on the drill press to get the countersinks all the same depth.

We have decided to reinforce the flap and aileron end ribs where the control horns mount by adding this angle bracket. This ensures the control load is transferred from the horn through the rib to the spar and skin with less chance of distortion.

In this photo the structure of the first aileron is taking shape while the second flap is being fitted with it's skin.