Thursday, October 11, 2012

Maintenance Check Flight

Cell phone technology is truly amazing, but it doesn't always work. Thursday I got my coffee and went into the office to check email and found I had missed a call from Harry. I called him immediately. Sally was back together but needed some tuning. Twenty minutes later I was sitting in the airplane ready to start.

It was a rough start. So he adjusted, I cooperated and together we worked through the morning to get her running smoothly again. But the weather was lousy with low ceilings and poor visibility. So I waited. By mid afternoon it had improved enough to take a lap around the field and all indications were good, except...High idle. Sally likes to land with no power and even a little throttle cause her to float. I think I must have bent the throttle arm trying to pull the power off, but a good slip and a little patience got us down at Butter Valley safely. Harry said that would be an easy adjustment. Now I wanted to do some more testing.

Friday was perfect. If she had been ready I would have started the trip, but I still had some questions. Preflight complete (looking very carefully at every hose, wire and engine component) I pulled her out of the hangar, climbed in and turned the key.  Smooth.  Next we taxied over to the little asphalt pad for an extensive run up. Nice. Next I sat on the runway and added full power while holding the breaks, which seemed like eternity but was really only thirty seconds. Power was good everything else normal. Once released she rolled down the runway and was ready to fly before the dip and hill, sooner than normal. So far so good.

Speed check. 6500' and 5450 RPM yielded 115 kts. Not as good as new but consistent with previous tests. I was satisfied that she passed that test. Altitude check. Up to 8500' at cruise climb speed (~75 kts), no problems noted. I was convinced she could go higher if I wanted to, but this was good. I was satisfied that she passed that test. Next I descended down and joined the pattern at N47. Idle still high I extended a bit and made a 'floater' but safe landing, then taxied over to pumps to top them off. I can count on one hand the number of times I've actually flown with a full fuel load.

Endurance check. I picked 4N1 as a way point which is just under an hour's flight north. I wanted to do a normal cruise, check all systems to be sure I didn't have any unexpected problems (like a  malfunctioning autopilot) and to make sure that running the engine under normal flight conditions didn't uncover any new issues. It was a pretty day, smooth air and the engine just hummed. I was satisfied that she passed that test.

So the only thing left to adjust was the idle. I put her back in the barn, pulled the cowling and checked everything. Clean and dry. I called Harry but he said he would be unavailable until Monday. Rats. I went home for lunch. Did I mention how great cell phone technology is? Harry called and said if I flew up to Slatington (69N ~ 20 minutes north) he would adjust the idle for me. Gee, that would mean I would have to fly twice in one day. Done deal.

It was a bit more than just a 'simple adjustment' but after a few trips around the pattern the idle was perfect. Harry suggested I get up to 4500' on the trip home to insure that the auto adjusting carbs still worked properly. I did, and they did. I was satisfied that she passed that test.

We were ready to go. Now if only the weather would cooperate. It didn't.

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