The angle of incidence (NOT to be confused with the AOA) is set to 2.5
degrees as measured at the wing root per the Builders Manual chapter on
"Wing to Fuselage Assembly". That is, the chord is 2.5 degrees up at the
leading edge, relative to the "waterline" of the fuselage (the waterline
reference in this case being the pilot's side door sill). Since the wing is
designed to stall first at the root, the angle of incidence decreases toward
the wing tip. I don't think that the manual tells us how much the angle of
incidence varies but it should not be necessary to know this for setting the
pitot tube angle.
Since a fixed pitot tube can not be set parallel to the relative wind except
at specific combinations of gross weight and airspeed, I suspect that what
Dynon really wants is for the pitot tube be parallel to the longitudinal
axis of the airframe, and close to the angle of incidence of the wing, with
compensation for any deviation from its preferred angle of incidence being
applied by calibration of the instrument.
Best regards,
Rob Housman
Irvine, California
Europa XS Tri-Gear
S/N A070
Airframe complete
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of
jimpuglise@comcast.net
Sent: Monday, July 23, 2007 12:52 PM
Subject: Europa-List: Angle of Attack
I am installing a Dynon ASI / AOA indicator. The pitot tube should be
parallel to the direction of flight when in cruise. In order to install it,
it is necessary to set it with reference to the chord of the wing, but I
don't see anywhere what the angle of attack is. I also thought the spar
might be 90 degrees from the chord but it does not appear that that is the
case.
How have others who are using the Dynon pitot tube set it?
Jim Puglise, A-283
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