Wednesday, June 23, 2010

tripping over a milestone

I pressed the hand-squeezer carefully, aligning the rivet sets, and as soon as I felt the first click of everything locked in place, I stopped and carefully eyeballed the various clamps, the angles, and the pieces of metal coming out. Take a deep breath, let it out slowly, and in that space between heartbeats, squeeze the trigg... the handles, feeling the rivet sets crush the soft aluminum between them. The machined head sat flush against the surface, trapped in the dimple with nowhere to go. The shank crumpled, expanding to fill the drilled hole, then out and down on the far side like a crushed pop can, forming a smooth cylindrical shop head. Carefully, ever so carefully, I look it out of the squeezer (which was stabilized in a vise), and over to the man with the Inspection Authorization.

He was working with a ring gear on an engine, installing a new belt for a starter, so I waited until he was done, then handed the rib to him. "So, tell me what I need to drill out and re-rivet." I said, and he grinned at me before lifting the long main rib to eye level and carefully scrutinizing each rivet in the many repairs.

There are so many ways for rivets to not be airworthy, and so few that are correct, so I waited, not even really expecting this to be the final repair. After four days of working on this rib, surely something else needed doing, or wasn't done to spec. All the same, there was a little knot of tension in my chest, and a small hope saying maybemaybemaybe...

"Looks good." He handed it back with a nod.

"Ah, excuse me." I said, then clasped it to my chest as a full girlish SQEEEEEEEEEEEEE! emerged, before I dashed off to clean it one last time before shooting a coat of zinc chromate on it. Behind me, I heard him chuckling as I managed to skip across the shop.

That's the last of the old ribs to repair - now to modify two butt ribs, then trammel both wings and nail the ribs to the spars!