There is nothing in the question to say that the airframe is dirty.
So we have to presume it isn't.
When in stable steady flight thrust equals drag.
And we are looking at the fast end of the drag curve not the dirty side.
So when the thrust is at a max the drag will be at its max for level flight and that configuration.
In fact even when the airframe is dirty as long as your level the max speed for that configuration will occur at max thrust which will also equate to max drag because of said graph and everything needing to be in balance.
Even in a descent discounting any of the limits airframe put on air speed, for any rate of descent the max speed will be at max thrust, which will be at max drag because otherwise the plane would accelerate. The only difference between this and level is the airspeed would be greater.
So looking at it we don't even need to presume the airframe is clean or that we are flying S & L.
Max thrust and min drag would give you the best excess energy which would be best acceleration or best climb.
MJ
I have just looked up swatton
section 13.3.3 page 98
"The maximum speed is achieved when maximum thrust is equal to the total drag"
Sorry Mr Swatton if this breaches copyright.
Last edited by mad_jock; 17th Jul 2003 at 22:41.