Tuesday, March 13, 2012

A Unique Historical Perspective

Through the immense power of the internet and the always helpful peer group of Van's builders, I was alerted to a problem that I didn't even know I had, to wit:

Dave - Good Monday! Was reading your Schmetterling blog over a cup a joe this morning and noticed something you may not be aware of.

The Vans plans don't actually tell you to do this, but the banjo bolt (the bulbous looking shiny fitting coming out of the bottom of the crankcase with the yellow plastic cap) has to be replaced with a flare fitting in order to mate with an oil return line. The fitting and a one page instruction sheet are in the small box of misc engine parts supplied by Rotax - the same box that the wrong fuel pressure sender came in.

I came to a screeching halt a couple of weekends ago trying to figure this out. A Monday morning call to Guss at Vans revealed that Rotax sometimes doesn't install the correct oil fitting for the Vans application, but supplies the fitting and an instruction sheet. Since Vans plans don't specifically tell us to do this, it left me stymied.

You have to drop the muffler to install this fitting and oil line, so don't bother silicone-ing your springs yet!

If you can't find the sheet, let me know. I'll forward it to you.

Also - when you take that yellow plastic cap off, oil will flow! (All over my muffler and nose wheel...!) You've been warned...

Hope this helps!
Well, I knew about the oil, anyway. The rest was surprising news. Upon examination this evening, I did find that my engine did indeed suffer from the presence of an unduly bulbous fitting. The replacement fitting was right there in the box, as predicted, but there was no sign of an instruction sheet.

While I was out there, I thought I'd knock out a couple of pages of work. I would install the knob/cable that will allow the opening and closing of the heater door from inside the cockpit. I will end up having to remove and replace the little panel that the knob mounts to because of the change in panel components brought about by the adoption of the Skyview avionics, but that won't be difficult. The majority of the work of installing the cable is in the mounting of it to the engine mount.

The first step is the fabrication of a firewall grommet. This is one of the weirder things Van's has us do - they have us create a larger diameter hole in the middle of a rubber grommet by using a socket as a die cutter. Basically we just crush the grommet with the socket until "a distinctive crunching sound" is heard. Of course, after the distinctive crushing sound that I heard when a tore the guts out of my vise while I was trying to open the angle at the ends of the longerons, I'm kind of leery about making distinctive crushing sounds with a vise.

Money, you know. It doesn't grow on trees.

And there is the newly widened grommet put safely to bed in the firewall.

I went ahead and ran the cable through. Gee, I hope it's long enough!

Most of its length will get eaten up in the circuitous, serpentine path that it will be taking on its way around the engine and over to the heater door. Nothing is left to just flop around on an airplane, so a cushion clamp is used to hold the cable in place under the panel shelf. I made repeated trips back and forth from the plans to the airplane trying to find the correct hole for the screw. You see, there were three available on the airplane, but the drawing only showed one. I ruled out the one that was too far away from the natural path that the cable wanted to take, leaving a choice of two. But which of the two was the correct one??

It took a very close examination to find the landmark that I was looking for. Ah, there's the other hole!

I remember not too long ago when I was thrilled to actually be able to sit in the airplane. These days, it's the precursor of a difficult job doing something under the panel shelf. Installing this clamp turned out to be easier than I had expected it to be, though.

It was the next one that caused all of the grief. This is one of those cases where the drawing in the manual masks a lot of the true complexity. Look how exposed those clamps are! Piece of cake!

I gathered up the clamps and attaching hardware, along with my extra-special cushion clamp installation tools.

Hey! Where'd all that extra stuff come from! None of that is in the drawing!! This is actually a more open path than I would have had if I hadn't known that I was going to have to remove the muffler anyway. I would have added another hour or so to the job of installed those first clamps just to avoid the five minutes that it took to remove the muffler. Odd, that, but it's just in my nature. I like a challenge! Conversely, I don't like work.

So, back there behind all of that stuff is the cable, patiently awaiting a set of clamps to hold it in place.

Installing that set of clamps was when I realized that building an airplane offers one a truly unique perspective on history. Sure, there's that whole Orville and Wilbur thing going on, but that's not what I'm referring to. No, I'm thinking that building an airplane gives one a unique opportunity to understand the history behind the English language. Case in point: installing these clamps was the precise type of situation that prompted the creation of the word "suck."

"Can you use it in a sentence, please?"

Yes, yes I can.

"Was it fun, educational, life-affirming, and all around rewarding to install those clamps? No, it sucked."

But eventually it was done! (Note the non-conventional orientation of the bolt - usually you try to go from the top down, but that would never have worked.)

There were two more to do, but they were right out in the open with the muffler removed. I found it easier to use the method that I learned with the oil vent hose: install the clamps, then push the hose/cable through.

I'm not sure what the purpose of the metal weave plate is, unless it was just a reminder of the utility of the work "suck." Kinda tricky to get that thing on there, it was.

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