Monday, January 23, 2006

Ok, enough with the safety wiring already...

It was a clear, sunny afternoon so I squeezed a flight in between work and school. The fuel tanks were low after the trip to Columbiana County and I don't like to let them stay at anything less than full in the winter, the conventional wisdom being that to do so is an invitation to condensation in the tanks. Tinfoil hat wearers may believe that engines would run on water if Halliburton would just stop killing off the scientists that know how, but the reality is that condensation in the tanks is a very bad thing. Or so I've been told. Does it matter? The plane needed gas and it was a pretty day, so I jumped over to MadCo to fill up. Just for the record, fueling up at MadCo, flying to and from Columbiana County, and returning to MadCo for more gas burned a total of 21.8 gallons. I'm not 100% sure of the economics of buying gas at MadCo rather than paying the higher price at Bolton, but again: it's an excuse to fly.

Nailed both landings. That alone maeks it worth it.

School was all work tonight. We started in the lab, where we learned to safety wire the turnbuckles that provide tension on control cables. I'd never done it before and I had been looking forward to it. Truth be told, now that I've done it, I think it would be nice to never do it again.

First of all, it requires using the thicker .041" wire, rather than the thinner and thus easier to work with .032" wire. Second, there's no fancy tool to make it easier. It's like learning to play the guitar: the wire hurts your fingers until you build up callouses. Third, and this didn't really become an issue until we went to the hangar to do it on planes, turnbuckles seem to be invariably buried deep in the hot, constrained bowels of the airplane.

The day classes don't do safety wiring on actual airplanes; that's a "benefit" reserved for us lucky night guys. Our instructor feels it important that we "get an appreciation" for what's it like in the real world. I jockingly asked if my five years on the Air Force flight line would allow me to test out of that, but no go. We all wandered around trying to pick an airplane that would have at least reasonably accessible turnbuckles. I started on the Comanche by removing the aileron bellcrank inspection plate (which came off quite willingly since it's probably been removed once a week for 30 years), but the turnbuckles there were very inaccessible, and actually saftied with clips rather than wire. I tried a greasy and very difficult to remove panel on the belly, but that only got me to the spar joint.

I finally gave up on the Comanche and moved to the Cessna 210 Centurion. This one had a rat's nest of an interior, the benefit of that being that the aileron cable turnbuckles were plainly visible inside the shredded headliner. Unfortunately, the cables run right up against the bottom of the wing, so there's very little room to work. The turnbuckles were all freshly safety wired, but the student prior to me had cheated and used .032 wire. No way I was going to be able to get away with that! It took 10 minutes and one very deep safety wire puncture in my finger to get the old wire removed. It took a very sweaty half hour to replace it. It looked pretty good, though, and it sure made the class fly by.

We didn't get to precision measurement tonight, which is kind of a shame since I've been practicing with the nice new micrometers I bought on my most recent unchaperoned visit to Harbor Freight. Wednesday will come soon enough, though, and it really was fun to do some challenging work in the hangar.

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