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Old November 15th 03, 05:55 AM
Peter Duniho
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"karl gruber" wrote in message
...
******Not necessarily. Depends whether you fly a low or high wing
aircraft.****

Not necessarily. The old Piper Cherokee wing pitches down with flaps. The
newer Warrior wing pitches up with flaps.

Has NOTHING to do with wing placement!!


Well, actually...

It has a little to do with the wing placement in that wing placement
certainly can affect whether flaps cause a nose-up or nose-down trim change.
Other factors are involved as well, so knowing the wing placement alone
won't tell you what flaps will do. But certainly, all else being equal,
moving the wing can change the way flaps affect trim.

Now, all that said...I don't think that's what Larry was talking about. The
trim change is usually a result of a combination of things, including
airflow over the horizontal stabilizer and elevator. But if I recall
correctly, flaps extended below the wing *also* create a pitching down
moment, always. This moment may be enhanced or obscured by other factors,
but it always exists.

Since trim changes often become negligible at lower airspeeds, this moment
can become more significant during the flare, even if the net trim change at
the normal flap extension speed would be nose-up.

At least, I think that's the point Larry was trying to make. I could very
well be wrong about what point he was trying to make, and I might have
misremembered this particular aspect of the aerodynamics of flaps.

Pete