Regarding altimeter errors, I had an interresting experience last month:
I had removed my instrument panel module for working on my autopilot
installation. As my altimeter (United) has been consistently showing a 2
to 2.5 millibars error for the last few years, I took this opportunity
to remove it and take it to an instrument shop for repair. After
overhaul I checked it was ok, then I install it back on the panel. The
next day, I was surprised to discover that the altimeter was wrong about
4 millibars, worse than before the overhaul! I removed it again from
the panel, and was ready to take it back to the instrument shop when I
found that the indication was now correct. After some thinking I
realized what happened: my instrument panel module is fitted with quick
disconnect fittings for both the static and pitot lines.Those fittings
have a shut-off valve. Therefore, when the panel is removed, the
altimeter is not connected to the ambiant static pressure anymore, and a
change in the atmospheric pressure will not be seen by the altimeter,
but, due to the thermal expansion of the air trapped inside the line,
any change of the temperature will!
Most Europas are fitted with those quick disconnect fittings at the port
wing root. So when your fuselage is at home on the trailer, do not be
fooled by the altimeter indication!
Richard,
Might be the reason of your problem. Please let us know.
Regards
Remi Guerner
<<<<<<<<<<It is a Wultrad I believe. It has been perfectly fine for five
years but
since the aircraft has been laid up for a while, it seems to be over
reading. My house is approx 50ft. above sea level but the altimeter is
reading 200 at todays pressure from local airfields.
Richard.. >>>>>>>>>
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