Rans ASI Fun
I’ve had similar issues with the Rans S6 Pitot / Static system over the years.
Seeing a good airspeed while not moving happened after re-skinning the fuselage. The Static side of the ASI vented at the back of the instrument. The new skin had a closure over the lacing on the underside of the fuselage, instead of the open lacing on the previous skin. While one could never accuse the Rans fuselage of being air-tight, there was enough pressure reduction caused by airflow from the propeller over the surfaces to ‘suck’ down the static side of the ASI. It showed about 45 MPH at take off RPM.
The other Pitot / Static problem manifested itself on departure from Tannkosh. Departing in trail with my partner and ahead of an Italian display team, I eventually noticed that the ASI needle was swinging around the scale in a haphazard fashion. That turned out to be a slug of rain water in the pitot system, drained at the next stop. Tannkosh did tend to get a bit of rain at night…
Safe Flying,
WKW.