Why does the shuttle throttle on ascent?

"John T" wrote in message
m...
"Ron Natalie" wrote in message
m

I don't know about G's but the shuttle adjust the engine thrust
up and down at various times in the launch based on the dynamic
pressures involved.

"'Go' for throttle up."

My generation's equivalent of "Where were you when Kennedy got shot?"

Even after many successful launches, always worry when I hear those words...

Mxsmanic wrote:
Pat Flannery writes:

On the P-51 Mustang, this was called "War Emergency Power"; it would
give some extra zip, but would also destroy the engine in around ten
minutes after engaging it. :-)

One wonders what sort of emergency would justify running the engine a
bit faster for just ten minutes, and then replacing the entire
aircraft.

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Ummm . . . a FW-190 (option: replace FW-190 with opponent on your six
.. . . really close . . . perhaps still there and shooting after after
what you have just finished what you used to think was your very best
move . . . in my book that rises to the level of an emergency. At that
point getting the pilot home was goal one.

Blue skies . . .

John

John

Dudley Henriques wrote:
If you are interested in a pilot report on what it was like to fly the D, I
did one for the Warbirdalley site some years ago at the following ;
http://www.warbirdalley.com/articles/p51pr.htm#pirep1
Hope you find the report interesting.



Thanks, I'll read that!

Pat

Getting shot at is not so bad, its the whatnot that will make you have a bad
day.
Jim in Houston
"Mxsmanic" wrote in message
...
tjd writes:

uh, you realize they were getting shot at and whatnot, right?

No, I don't. I've never flown in combat.

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On 2007-01-07, Danny Deger wrote:

"Tony" wrote in message
ps.com...
You airn't never been lost until you've been lost at Mach 3. I learned
that bit of wisdom from an air force jock. I can get lost at 150 kts.


I have never been lost in an airplane. Though, I have suffered from
temperary disorintation due to poorly designed maps :-)

I'm never lost - I'm always "here". The big question is of course where
"here" actuallyl is.

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Oolite-Linux: an Elite tribute: http://oolite-linux.berlios.de

"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

I believe the guys are getting their fuel from a specific source, but I'm
not sure who handles that now.
Dudley Henriques

"Taylor" wrote in message
...
Dudley Henriques wrote:

"Pat Flannery" wrote in message
...


Morgans wrote:

Of course, on some engines, that was grounds for grounding the aircraft
to inspect the engine, to see if it was damaged from exceeding 100%
power.


On the P-51 Mustang, this was called "War Emergency Power"; it would give
some extra zip, but would also destroy the engine in around ten minutes
after engaging it. :-)

Pat


Actually it's 5 minutes. WEP on my V1650-7 Merlin in the 51 could be
achieved by breaking the throttle gate . I never used it...actually never
needed it really. Under 5000 feet, normal max power at 61 inches gives
you all the power you need to exceed the operating limitations for the
engine, and at altitude on cross country, I was more concerned with
saving a buck by not stressing the engine anyway :-)
Also, if breaking the gate and using that extra 6" of MP, the Mustang
should be using 130 octane fuel and not the 100LL we poor folks have in
the tanks most of the time :-)

Does anyone still make the purple juice for the air races? I recall that
Phillips 66 used to...

John writes:

Ummm . . . a FW-190 (option: replace FW-190 with opponent on your six
. . . really close . . . perhaps still there and shooting after after
what you have just finished what you used to think was your very best
move . . . in my book that rises to the level of an emergency. At that
point getting the pilot home was goal one.

OK, but if you can only fly at emergency war power for five minutes,
and if it only offers a moderate advantage over normal maximum power,
it seems that there would be relatively few situations in which it
would make a difference. Either you'd be out of luck to begin with
and EWP wouldn't get you out of it, or you wouldn't be in danger and
so you wouldn't need EWP.

If EWP can give you an extra 50 kts, for example, at best you'd have
an advantage of five nautical miles when the engine disintegrates. If
the bad guys are only 30 knots slower, your advantage shrinks further.
And with a blown engine, you'll need to be completely out of danger
after five minutes, or all that effort wouldn't help.

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Mxsmanic wrote:
John writes:

Ummm . . . a FW-190 (option: replace FW-190 with opponent on your
six . . . really close . . . perhaps still there and shooting after
after what you have just finished what you used to think was your
very best move . . . in my book that rises to the level of an
emergency. At that point getting the pilot home was goal one.

OK, but if you can only fly at emergency war power for five minutes,
and if it only offers a moderate advantage over normal maximum power,
it seems that there would be relatively few situations in which it
would make a difference. Either you'd be out of luck to begin with
and EWP wouldn't get you out of it, or you wouldn't be in danger and
so you wouldn't need EWP.

If EWP can give you an extra 50 kts, for example, at best you'd have
an advantage of five nautical miles when the engine disintegrates. If
the bad guys are only 30 knots slower, your advantage shrinks further.
And with a blown engine, you'll need to be completely out of danger
after five minutes, or all that effort wouldn't help.


You are absolutly right Anthony and all of the combat aircraft designers,
builders and pilots were silly for adding and using the feature. It is a sin
that you weren't around at the time to explain the them the error of their
ways.

Taylor wrote:

The foam wouldn't move rearwords...the shuttle would move forwards.

Well, if you're going to split hairs, both the foam and the Shuttle
would still be moving forwards- it's just that the Shuttle would still
be gaining velocity and the foam traveling forwards at whatever velocity
it fell off at.

Pat