Tuesday, September 21, 2010

Back at Work - Tip Bow install

Today was a very long day - not by the clock, but by the "I am so very exhausted I can't think straight." It was the first day back from sick, and I may have pushed the timetable a little too much. Airplanes are not good to be working on when tired - few of the mistakes you can make are trivial, and many result in injury. So until the caffeine kicked in, I cleaned the dirty engine.

Under all that glacial silt is a beautiful engine, lovingly preserved - the borescope inspection yesterday proved that the work put into pickling her and regularly baking the desiccant plugs has paid off with shiny clean cylinders inside, ready to fire and fly. I took the four spark plugs out of careful storage, and laid them next to the tools for the last person working on the engine - they shall be ready to exchange places with the desiccants when we put her back together.

Then I started carefully filing the notch in the front spar for the tip bow, and marking the places to drill on my spar for the tip bow attachment bolts. When the bow fit as perfectly as I could make it, I drilled both spars, varnished the notch and all four holes, attached the hardware, and added a drop of varnish to each washer and nut to help secure and seal them. Then, I screwed the top and bottom of the tip rib to the back of the bow, and cut the rib so it wraps neatly around the tube. (The repair was a little too long - when it was taken off the tip rib, the rib ends were not unscrewed and were torn away.)

When I drilled the new anchor on the tip noserib, I discovered to my dismay that I should have drilled that before installation - there wasn't enough room to get a good angle with the lengths of bits I had. Enter a new tool that's just neater than kitten toes - a right angle drill!

With that, I got the tip bow completely secured. Still feeling tired, I decided to start modifying the crude rough-approximations of leading edge tip pieces to fit. It was a better idea than trying to work with the hole cutter and my hard-to-replace scarce amounts of aileron cove. Sheet metal work, at worst, can be redone from scratch. I got four out of 5 pieces done well - the rootmost piece was a failure, as it I shaped it, fit it, marked it, cut and bent it, fit it, did the final trim - and suddenly it didn't fit.

That was a good time to stop, call it a day, and watch the A&Ps work on installing a windshield.

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