Saturday, January 7, 2012


Sunny skies and very nearly 60 degrees?? Wow, spring is a little early this year! Usually the weather this time of year adds ten to fifteen percentage points to my overall stress and anxiety level because of the constant threat of ice, sleet, snow, slush, and countless other forms of solid, commute-destroying precipitation. Knowing that the type of benign weather such as we've had so far this year is building up a huge negative balance in our climate karma, a balance that must surely be reconciled in the near future with apocalyptic storms, I decided that I had to get out to the hangar for at least a token amount of airplane work despite being tired, irritated, frustrated, and generally worn out after my first week back in the uranium mines.

Only to be greeted with this:

That pile of processed dinosaur fluid wasn't there when I left after hanging the engine! Lions and tigers and oil leaks -- OH MY!

So, yeah, a moment of panic. Mostly, as it turns out, because I haven't taken the time to read the Rotax engine manual. This engine is different from those that I'm used to in many ways, including the fact that the oil return fitting is down on the bottom where the sump would be on the type of engines I'm used to. The Rotax is a dry sump engine, which is a bit of a misnomer, in my opinion. There is, in fact, so sump at all, dry or otherwise. There will actually be an oil tank mounted on the firewall. The leaking oil is coming from the hose fitting that will provide a path for the oil to route through the oil cooler and thence back to the tank.

Someday, anyway. For now there's just a not-quite-leak-proof plastic cap on the fitting.

One of the problems left over from the engine mounting was that of the not-quite-right cotter pin fit. Part of the problem there was that the team (note how I deflect/amortize the blame across the entire team rather than focus it where it belongs: directly on me, the manager; if I've learned nothing else from my years in Corporate America.... and watching the antics of our gov't....) missed the call out for a washer between the engine mount and the castellated nut. Two washers were provided with the kit for that purpose, but it actually took both of them to correct one side.

Needing a couple more washers, I had to place an order with Aircraft Spruce. The washers only cost $.03 each, but the shipping was $.75 - a small sum indeed, but it automatically triggered that spot in my brain that insists on adding things to the order to reduce the parts-to-shipping cost ratio. And the thing is, there was something I've needed to order for awhile now and haven't done so because of the same cost ratio problem.

Could I remember what that thing was?

Of course not.

I'd have to wait for the washers to show up to finish that job, but I still had time and energy enough to do a little more work. The next steps are the installation of some of the fuel lines. The first attaches to the input of the fuel pump:

The other end gets attached to the output of the gascolator. I still remember installing the gascolator a couple of years ago and being very happy about it - it was the first real "airplane part" of the entire build. My, we've come a long way, haven't we?

The next hose is, I think, the fuel return hose. This hose will return fuel back to the fuel tank. Again, due to my abject laziness and failure to read the engine manual, I don't know what conditions cause fuel to need to be returned to the tank. I suspect it is at least partially the case that a fuel return line helps avoid vapor lock in a hot engine, but I really don't know.

The hose gets attached to the fuel line traffic circle, yet another part of the engine that is a complete mystery to me. Once attached, I grabbed my little tube of Torque Lock to put the mark on the bolt that tells me that I've tightened it to its final torque. Yes, that would be the nearly empty tube of Torque Lock that I needed to replace with my next Aircraft Spruce order....

The other end of that hose gets attached to the fuel pressure sender (which seems odd, and only confuses me more about what all of these hoses do), but because I don't actually have a fuel pressure sender, that job also had to be deferred.

Because the temperature was a full forty degrees warmer than what we had when I tried and failed to get the big hose springs pushed into the radiator hoses, I decided to test my theory that the difficulties I encountered were due to the bitter cold. Sure enough, the springs went in far more easily in the more reasonable environment. The only problem I ran into was with the 30" hose. The spring has to pushed in one inch past the end of the hose, and I couldn't find a way to do that with pliers. I came up with the brilliant idea of using a socket to pound the spring further down into the hose.

Unfortunately, my brilliant idea failed to consider that I was pounding on a spring, and naturally that spring did what springs do: it sprang. While I did make some progress, I was still short of the required inch:

It took nearly the full length of the socket to get the spring pushed far enough into the hose that its recoil would leave it at the requisite depth, which unsurprisingly made it very difficult to get the socket back out.

That was enough work for the day; I finished up by just spending a few minutes soaking in the sights of an airplane with an engine attached basking in the warm glow of a very nice sunset.

Still, at some level my enjoyment was tempered by the fact that I dread the inevitable weather reckoning.

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