On May 7, 12:49*am, Stealth Pilot
wrote:
On Mon, 5 May 2008 16:55:37 -0700 (PDT), WingFlaps

wrote:
On May 6, 10:52*am, wrote:
On May 5, 1:38 pm, WingFlaps wrote:

Does the elevator lift force and *stall angle reflect trim setting at
all?
Cheers

absolutely not!


Sorry you are wrong and let me try to explain why. Let's say you've
trimmed nose up, the elevator is deflected up but the trim surface is
deflected down. Where is the chord line of the tail? The chordline
where the trim tab is absent has a negative AOA so the tail lift is
downward. In the region of the trim tab, the angle made by the
chordline (and therefore AOA) is _reduced_ and the lift is reduced
also. -sketch it on paper and you will see it (remember the chord
runs from the trailing edge to the leading edge). Now imagine the
pilot wants to go into a fast dive. Now the elevator points down and
in this case the AOA in the region of the trim tab is increased over
that of the rest of the elevator. In this case, the trim has increased
tail effectiveness (albeit at a higher stick force) by increasing
local camber and that was correctly seen by Bertie.

I hope you can see it now.

Cheers