Saturday, October 2, 2010

Picture Progress - Leading Edge

Quick summary - after the aileron cove, I've been concentrating on the leading edge, then the base for the gas tank cover. A few highlights and lowlights follow:

Here we see a mistake. That panel standing up on the floor? Yeah, that's a 0.020 thick panel while the rest of the leading edge is 0.016 - I intended to put that down by the gas tank. Unfortunately, I did not mark the outside of the panels, and when coming back from very sick, then tired, I never thought to look and differentiate. By this time, the panels have been cut to length (and the place where I put it was the only panel not cut to length, or I would have noticed earlier). I can't swap it now.

The .016 thick panel at the gas tank's leading edge needs to survive years upon years of neglect and abuse in the form of gas tanks, fuel nozzles, hoses, ladders thumping into it, and elbows resting on it. All of these are bad ideas, but nigh-inevitable with new students, or klutzes. So, I put a second layer of 0.020 metal beneath the surface most likely to be whapped or thumped, cleco'ed it in place, and took out a cleco at a time to screw it in. Hopefully, .036 thick will survive and look good for the 30-40 years till I need to recover! As a side note - the original leading edge was .010 thick. The weight penalty is noticeable, but the tradeoff is not denting your leading edge by hitting a large mosquito at speed.

All the panels except last on the tip in:

There's an aesthetic reason that tip panel was left for last - the spar sticks out a little near the tip bow, and the edges if left alone will stick through the fabric. This will rub and chafe the fabric. More importantly, we refer to airplanes as female, like sailing ships, and very few women can pull off looking good with their bones pressing out tight against skin. (Okay, outside of Oleg Volk taking their photos - that man can make even me look beautiful!) A little shaving and applying more varnish does not noticeably detract from strength and flexibility if done correctly, and vastly improves her look.

Once it was all in, I cut the notches so I can get the straps in around the gas tank, and work on both sides of the spar should I ever need to.

In addition to the reinforcement for the first panel, I spent a good chunk of time designing and fabricating other metal parts for the tank cover base, and a stiffener for the bottom of the butt rib. (The original butt rib had a triangular stiffener on top and on bottom, but the tank cover will be a stiffener on top.)

The shorter metal piece is shown here as the crosspiece in the back of the gas tank base. This has since had a lot of markings, fingerprints, a few dings, and nutplates added in - all the ones I could install with the hand-squeezer are in, and I'll use the impact riveter on the others with close supervision and help Monday. My IA made new aileron cables today. Last time I tried, I injured my shoulder - he's satisfied I have the theory, have seen and tried the application, and don't need to risk reinjury. Four more nutplates, installed cables (and supports, if necessary), and I'll be ready to cover!


phlegmfatale said...

wow. That's really cool!

Rev. Paul said...

The amount of time and energy expended would be daunting, if it were not a labor of love.

Old NFO said...

You do good work there Wing :-) And we ALL make mistakes too! At least you found it early, rather than late...