Hi everyone,
I thought to be smart and ordered from RS the "upgraded" versions of the
standard Europa static and pitot connectors. These are not floating but
have a thread and nut so I can fix them on the fuselage. As a bonus (I
thought) they have an automatic valve that closes when they are not
connected, so no moisture or bugs can creep in.
So far so good. The system is leak free (as tested with a syringe to
simulate pressure changes), over a couple of hours indications of ASI
and altitude didn't change.
However, I noticed now that with the wings disconnected, when the
ambient temperature or pressure changes, the instruments start to
indicate airspeed and altitude values, because the pressure inside the
static and pitot system can not vent. Of course the pressure difference
will leak away over a couple of days, but the leak rate of the pitot and
static are not equal so in the mean time weird things happen.
One thing that concerns me is what would happen when the pressure in the
pitot is lower than in the static port: the ASI would want to indicate a
negative value. This will happen when the ambient pressure increases and
the leak rate of the static port is higher than the pitot.
Should I abandon the idea of using the connectors with automatic valves?
Or should I intentionally introduce a small leak between static and
pitot so ambient pressure changes will not wreck havoc with the
instruments? Has anyone else a similar setup?
Frans
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