I had an interesting experience yesterday when attempting a permit test flight.
Had my plane at home for a 50 hour check and its annual inspection. Trailered
it down to the field for test flight but on the first take off run noticed that
the ASI was stuck on zero. Aborted the run and checked the pitot. All looked
Ok. gentle blowing into the pitot made the ASI twitch. Tried a rubber pipe on
it and rolled it up to produce pressure. ASI responded OK and held the reading.
Attempted a second run with same result. Still no air speed indication. On
further examination I noticed hat the plastic tip rom the static port was
missing.
Obviously the static pressure was the same as the pitot hence a zero ASI
reading. As an emergency temporary fix I disconnected the static pipe at a
connection
inside the cockpit which then gave me a satisfactory reading and I was
able to do the test flight OK. Comparing airspeed to GPS it seemed fairly
accurate.
I guess somewhere along the line I must have caught the plastic tip and
broken it off. It would seem to be a vulnerable arrangement and wondered if
I could get a more robust replacement or locate a static port somewhere else to
avoid a repetition?
Richard Iddon.
G-RIXS
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