I just found this old photo that explains quite a lot.

When I bought G-AWGN, Wagon, or the Red One, there was a whole bunch of things wrong with it.
Some I have already mentioned, like all the loose objects in the fuselage.

Another problem was that the altimeter seemed to lag a lot, and often jumped fifty feet or so when I was going vertically up or down, despite checking out OK on the calibration rig.
I wasn't too sure about the ASI either.

So, to save a lot of work removing the instrument panel, I stuck my new mobile phone (cell phone) up behind it and took a few photos.
This one shows precisely what the problem was.
It's the static line coming off the back of the altimeter.
So of course, I had to remove the panel anyway!

Notice that, as well as being kinked so tightly against the fuel tank that there was very little pressure getting to and from the intrument, the line was not secured (clipped) in any way, and there was nothing to prevent it vibrating and abrading its way into the fuel tank.

Great maintenance eh?

It was easily fixed by replacing the altimeter by one with a shorter tube out of the back.
Needless to say, the static line is now properly secured, too.

Yours, Bob

[Edit by Bob Grimstead on Tuesday, February 1, 2011 @ 06:08 AM]

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