Follow-up thought:
Would you go out to the Cessna or Piper on the flight line and glue an air-dam just in front of the static port on the side of the plane to create turbulent air across the static port and expect good results? They put effort into choosing the location of the static port so the airflow is smooth and parallel to the surface where the static port emerges. The design of the static ports around the cylinder of the Coupe pitot/static probe does this pretty well. The ring makes it just like putting an air dam in front of the static port on another airplane type. As you say, the proof is in the pudding. Is the airspeed accurate and stable in all airspeeds and attitudes? Ed _____ From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of Ed Burkhead Sent: Wednesday, May 07, 2008 10:27 AM To: 'WILLIAM BIGGS'; 'Mitchell Williams'; [email protected] Subject: RE: [ercoupe-tech] Pitot Tube Calibration Ring Bill, That complex cylinder pitot/static tube was the original equipment on the Ercoupes. As far as I know, it carried through all the Ercoupes and, I'd expect, the entire Coupe line. I don't know if it was unique to Ercoupes or if other planes also used it. It has a cup-shaped depression on the front with a central, raised bump and the pitot tube openings are on the sides of that bump. On the sides of the cylinder, equally spaced around it, are static port openings. I'm guessing that this design allows fairly reliable and consistent airspeed readings even when the plane is in a slip. On a plane with a non-Ercoupe pitot/static system, well, you're doing something else. Ed
