I don't think any of us, (including Barry Tennant) would disagree with Dave
Conrad's aerodynamics, but we might disagree with his implication that
Barry's contribution was not useful and valid. It is apparent from Barry's
figures that the wash from the propellor over the wings, in the
configuration and at the speeds stated, provides enough additional lift to
stop the aircraft from 'settling' (and thereby increasing the angle of
attack to the point of stall) at a speed as much as 13 kts slower, than
when the wings only have the benefit of the wind from forward motion. In
circumstances where the pilot gets airborne involuntarily while taxying he
will not have the height to stop the stall by pitching forward, but he does
still have the engine, and its apparent ability to provide additional lift
---From the propwash. 747 pilots need not copy!
Frank Mycroft
|