Brief Description: Tom Clark fastback - canopy frame
I somewhat naievly thought that cutting the canopy frame and adding the modified aft support tube would be a *relatively* straightforward task. Oh how wrong I was! Cutting the frame was easy enough; 5 minutes with the angle grinder saw to that. But when I placed it back on the fuselage I spotted the problem. The aft sides need to be spread 2" further apart to match the new Tom Clark F-807 bulkhead.
Hmm, simply spreading the tubes is no good because then the side tubes overlap the fuselage. The aft tubing actually has an inwards bend to it. Well, I tried bending it back out but that didn't work and I was really concious of kinking the existing tube. I managed 1" on one side. Next I realised that this wasn't going to be the answer either, because again the bottom would be too far out. What was needed was atwist so the upper tube comes out the extra 1" but the lower tube stays in the same place. This is unlikely to happen since one of the uprights, or 'ribs', will probably prevent it. So I think that upright tube needs to be cut away and then re-welded after the bend is completed.
At this point I'm coming to the conclusion it will take more re-work than I am capable of on my own. I have the phone number for a guy that does aircraft welding, so I will call him next week and see if I can enlist his assistance before I wreck a very expensive canopy frame!
