Sunday, April 14, 2013

A Premonition

I had hoped, again, to fly out west for a visit to Schmetterling's home office, but yet again I was rebuffed by a forecast for uncomfortably hearty winds in the afternoon.  This time around it was 12 gusting 20, coming straight out of the south. The runway at Darke Co. points east/west so I would be taking the full brunt of it early in the takeoff roll, precisely when it can do the most damage. I canceled the flight and arranged to have Pete come over to the hangar to help with a few maintenance chores instead. Which reminds me: I received yet another service bulletin. This is the cost of being an early adopter, even if not in the first phase. As some of the older and more heavily used RV-12s get a significant number of hours on them, wear points are starting to show. Van's, to their credit, often develops a fix for the planes in the field and sends along any required parts and directions free of charge. Still, I cringe when I get one - some can be quite tricky and time-consuming to deal with.

There was no hurry to get to it, though, so we agreed that we would start after breakfast. We usually meet at the nearby Steak & Shake. We started meeting there after getting tired of $10 omelets at Bob Evan's and $3 krep from McDonalds. Steak & Shake is somewhere in between. It also helps that we have a regular waitress there that we really like. In fact, even the Sunday mornings that involve an early AM grocery shopping trip with the CFO as often as not end up with us visiting Kassie at Steak & Shake. 

I was thinking as I walked from the car to the front door of Steak & Shake that I don't know what we would do if Kassie stopped working there. In fact, I thought, I should tell her to make sure to let us know if that ever happened. Well, I never got the chance. My stray thought turned out to be a premonition.  As she met me at my usual booth with my coffee, she told me that she is moving to Phoenix next week.  

Rats.

Once we finished eating and got to the hangar, I had a small job to do before starting on the service bulletin. While it didn't rise to the criticality of a service bulletin, it had come to my attention that Van's had redesigned the way that the canopy lift struts attach to the side of the fuselage. The old style had a simple bushing between the canopy strut and an aluminum angle piece riveted in place as a support. The bushing was not up to the task and eventually started to loosen up and wobble. Even with only 12 hours on the clock, mine too was demonstrating the weakness.

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After the replacement bushing is installed, there is a notable difference.

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It didn't take long at all to install the new bushings. First, the old bushing is removed. It's the one on the left. The new bushing, as can be seen below, is milled to fit into the hole on the end of the strut.


Thar required that the hole be dripped out to 3/8".  I was afraid that the brutality of a Uni-bit would leave a hellacious mess, but it actually turned out a nice, clean hole.


The bushing was a snug fit, but a pair of channel lock pliers encouraged it into the strut nicely.


There is a new washer required, too.


It bolted in as easy as could be.  Both sides combined took less than fifteen minutes.


So then it was on to the service bulletin. The cause of this particular change request was that the weight of the oil tank was causing cracks in a supporting bracket. The fix is to install a massive (relatively) new bracket at the bottom of the tank mount.  That would require removing the cowls. I would normally object to that, but after twelve flying hours on a brand new airplane, I thought it nigh time to get in there for an inspection anyway.

The included directions had us remove the battery and drain the oil from the sump. I removed the battery agreeably enough, but balked at draining the oil. I just removed the tank clamps and move the tank up out of the way.

  

I stuffed the new bracket in place to see if it fit.



Holes needed to be drilled through the outside of the main tank support and into the flanges of the new bracket. I measured the distance from the bottom of the bracket to the rivet line onto a piece of paper, cut a piece of it off, and used it to market the target line.


Some of the holes were impossible to get at from the outside in, so I drilled them from the inside out. That turned out to be the easier way to do it, in fact.


I very cleverly drilled the first hole such that the cleco, which wouldn't go in from the other side, was completely in the way of drilling the second hole.  Brilliant!


This hole also had to go from the inside out, but it was going to require drilling through a relatively flexible part of the tank mounting bracket, so I clamped the mounting bracket in place.


All in all, I think the service bulletin took somewhere between 30 to 45 minutes.  

As long as I had Pete's help, I had him press down on the tail so I could get a sawhorse to support the fuselage with the nose wheel off the ground. I wanted to loosen the torque nut one flat to see if that would make the steering less squirrelly in cross winds. That was easy enough, but because the hole for the cotter  pin had been positioned for what at the time was the correct torque, moving the nut down (by loosening it) left very little room for a new cotter pin to fit. That required a hammer to fix.

Another little thing that had been bugging me is that I don't have easy access to pens in this plane. I found an old pen holder and installed it where I would be able to reach it. The map box is just too far away when the shoulder straps are snugged down.


After finishing up the hangar work, I headed home for the first mow of the season. Being as I haven't mowed for so long, I seem to have at least partially forgotten how to drive the new zero turn radius mower. Unfortunately, I had to re-learn a hard lesson: because of the way the front wheels swivel, it is possible to get the mower into tight areas that you cannot back out of. And thus two new scars were added to the dozen or so that I have already put into the house with this mower.

Later, as I was putting the mower away, it struck me: normally mowing in high winds is a horrible experience, what with grass clippings blowing all over the place and getting inhaled or caught in my eyes. That didn't happen. I went in the house and checked on the weather: 7 knot winds out of the east. The forecast was wrong. As disappointing as that is, you just can't take the chance on them being right - 12 gusting 20 was not something to be trifled with.  Not at this stage of my experience with this airplane, anyway.


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