Started on Feb. 19, 2010 Build Time 23 Hours
Construction of the main spars started with removing the protective plastic from each spar. I decided to work on both wings at the same time rather than each individually.
Located the main spar web extension and spar splice plates. Clecoed them into place and final drilled with a #30 bit. You then take them off mark them so they can be orientated in the same way they were final drilled. I then deburred, prepped them for primer, then primed.
Once the primer had dried, it was time to re-cleco the splice plates and extensions back into place and rivet with AD4263-4 rivets.
Next was to fabricate upper, lower, top and bottom wing box J-stiffeners. Cut to the length specified and then used spring cleco clamps to hold them on to the main spar flanges, making sure that there was 1/16th sticking up above the spar flange. Once in place, match drill with a #40 using the holes in the main spar flange as a guide.
Once completed, they are to be removed and stored for later on in the wing construction. I decided to deburr and prime them before storing.
Now that the wing box stiffeners are removed, you run a #40 drill through every 3/32 hole that was not already drilled. There are a lot of holes.
Then on to countersinking all the holes. Using a countersink stop, I set it first to do the fuel tank nut-plates and the holes for attaching the side of the wing ribs, the set a bit deeper for countersinking the skin attach holes. These are a bit deeper because it has to accept the dimple from the skin instead of just a rivet head.
Now that all the holes are countersunk, I prepped and primed the holes for the alodine that was removed. Once dry, started to rivet on all the nut-plates, 66 per spar. After all the nut-plates are riveted in place, the nut plate screw holes must be countersunk to accept the skin dimple and a #6 or #8 screw. The nut-plates must be riveted on before this task because you use the nut-plate screw hole as a guide. Then again these holes must be primed where the gold alodine has been removed.
Finally all the holes have been drilled out, countersunk, nut plates riveted in place and all holes re-alodined and primed.
The next step was to fit the fuel tank attach nut plates and wing attach nut plates in the web of the inner spar. Good thing I double checked all these plates because at first I had them placed on the wrong side of the spar. Good of been a bad mistake.
The holes have been match drilled, primed and nut plates riveted to the spar.
It was now time to fabricate the tie-down brackets. I decided not to use the factory supplied pieces and went to Cleaveland Tools and purchased the already threaded blocks. They still needed to be cut to size but at least the threads were already done.
The tie down blocks have been clecoed to the spar, holes match drilled, nut plates drilled and ready to be attached but first prepared the tie downs for primer and primed. Nut plates were attached after the primer dried.
The last step of the wing spar is to attach the tied down brackets to the spar and bold on the Aileron Bellcrank Brackets. All rivets are in and bolts torqued to specs. On to the wing ribs.