Re: Jet Engines above the wing: why not used?

From:         Tony Maddern <tmaddern@cse.unsw.edu.au>
Organization: University of New South Wales
Date:         20 May 96 10:13:18 
References:   1 2 3 4
Followups:    1
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Tom Speer wrote:
>

> I doubt that causing a pitch up with the application of power is a major
> design driver in the positioning of engines.  I know of no flying
> qualities requirement for this.  Even if were required, the aircraft
> speed stability may result in a pitch up even for engines mounted
> some distance above the c.g.

I believe there is a certification design requirement for an increase
in thrust/power to cause a pitch up in order to cover the go-around
from low altitude case. A nose down pitching moment close to the
ground would be most undesireable whereas a nose up pitching moment
will assist in rotating the aircraft to the go around attitude. Speed
stability will only come into effect once airspeed has been increased.
TM