Why does the shuttle throttle on ascent?

"Morgans" wrote in message
...

"Dudley Henriques" wrote

I flew a D, as well as various other prop fighters as a civilian
operator. Never flew ours with external tanks. The airplane is stable on
takeoff if flown correctly and I wouldn't anticipate any specific issues
with the external tanks except the extended run. I believe the only
caution on the external tanks was for high speed buffet above 400 mph.
We had the fuselage tank removed and only flew the Mustang using the 2
mains at 92 gallons each.(90 usable)

I had always heard that the fuselage tank was the source of the
instability, with it being so far behind the CG, to give it a dangerously
aft CG. Today, in peacetime, I don't suppose they would ever dream of
putting that much weight that far back, but it was war.

Comments?
--
Jim in NC

The fuselage tank held 85 gals of fuel and did indeed bring the cg back
causing a real change in flight characteristics. It really screwed around
with the pitch moments. It could be handled, but the general word was for
pilots to take the bird out with fuel in the tank and go upstairs and do
some "getting used to it" flying.
The danger point where it actually became a cg issue began at about 25 gals.
The flight characteristics got worse with more fuel in the tank over that 25
gals. At 40 gals in the tank, anything involving maneuvering flight was a
toss up for pitch control.
Dudley Henriques