747 engine takeoff power

Gord Beaman wrote

John, I recall that you're a qualified 747 F/E or Pilot so can
you tell me whether replacing aerodynamic trim of the tailplane
with fuel weight to reduce drag during cruise is still being
done?...I never seem to hear of it anymore, also what's the
proper nomenclature for that?

We never did the fuel thing in the B-707, but we did try
to keep as much luggage/cargo in the aft hold as possible
in order to accomplish the same thing.

Bob

Bob Moore wrote:

Gord Beaman wrote

John, I recall that you're a qualified 747 F/E or Pilot so can
you tell me whether replacing aerodynamic trim of the tailplane
with fuel weight to reduce drag during cruise is still being
done?...I never seem to hear of it anymore, also what's the
proper nomenclature for that?

We never did the fuel thing in the B-707, but we did try
to keep as much luggage/cargo in the aft hold as possible
in order to accomplish the same thing.

Bob

Thanks Bob...
--

-Gord.
(use gordon in email)

"Gord Beaman" wrote...

John, I recall that you're a qualified 747 F/E or Pilot so can
you tell me whether replacing aerodynamic trim of the tailplane
with fuel weight to reduce drag during cruise is still being
done?...I never seem to hear of it anymore, also what's the
proper nomenclature for that?

I'm a 747-400 Pilot.

Some 744s were delivered with fuel tanks in the horizontal tail. They hold
10,000 Kg. I have not flown any airplanes with them installed, so I do not know
any fuel management specifics for them.

While it may be possible to "passively" manage the CG by retaining the tail fuel
as long as possible, I don't know if this is authorized. Also, AFAIK, there is
no way to move fuel to the tail tank in flight -- once transferred down, it
stays down.

"John R Weiss" wrote:

"Gord Beaman" wrote...

John, I recall that you're a qualified 747 F/E or Pilot so can
you tell me whether replacing aerodynamic trim of the tailplane
with fuel weight to reduce drag during cruise is still being
done?...I never seem to hear of it anymore, also what's the
proper nomenclature for that?

I'm a 747-400 Pilot.

Some 744s were delivered with fuel tanks in the horizontal tail. They hold
10,000 Kg. I have not flown any airplanes with them installed, so I do not know
any fuel management specifics for them.

While it may be possible to "passively" manage the CG by retaining the tail fuel
as long as possible, I don't know if this is authorized. Also, AFAIK, there is
no way to move fuel to the tail tank in flight -- once transferred down, it
stays down.


It's really amazing what poor info one can gather on these ngs
isn't it?...I know for a fact that I've been told by those who
appeared to be authentic 747 aircrew that moving fuel to and from
the tail tank was used to replace aerodynamic fore and aft trim
to reduce drag on long cruise legs. Apparently this reduced the
stability so much that it could only be done with a serviceable
autopilot. And that it was only done during cruise, never for any
other phase of flight.

I understand that the basic reason for the Soviet Aeroflot
aircraft inflight breakup and crash several years ago was due to
the captain's son horsing the controls 'out of autopilot' during
this phase of flight and the subsequent violent motions prevented
recovery until some major structural failure had occurred.

Thanks for the info John, I appreciate it.
--

-Gord.
(use gordon in email)

"Gord Beaman" wrote in message
...
"John R Weiss" wrote:

"Gord Beaman" wrote...

John, I recall that you're a qualified 747 F/E or Pilot so can
you tell me whether replacing aerodynamic trim of the tailplane
with fuel weight to reduce drag during cruise is still being
done?...I never seem to hear of it anymore, also what's the
proper nomenclature for that?

I'm a 747-400 Pilot.

Some 744s were delivered with fuel tanks in the horizontal tail. They
hold
10,000 Kg. I have not flown any airplanes with them installed, so I do
not know
any fuel management specifics for them.

While it may be possible to "passively" manage the CG by retaining the
tail fuel
as long as possible, I don't know if this is authorized. Also, AFAIK,
there is
no way to move fuel to the tail tank in flight -- once transferred down,
it
stays down.


It's really amazing what poor info one can gather on these ngs
isn't it?...I know for a fact that I've been told by those who
appeared to be authentic 747 aircrew that moving fuel to and from
the tail tank was used to replace aerodynamic fore and aft trim
to reduce drag on long cruise legs. Apparently this reduced the
stability so much that it could only be done with a serviceable
autopilot. And that it was only done during cruise, never for any
other phase of flight.

I understand that the basic reason for the Soviet Aeroflot
aircraft inflight breakup and crash several years ago was due to
the captain's son horsing the controls 'out of autopilot' during
this phase of flight and the subsequent violent motions prevented
recovery until some major structural failure had occurred.


Well yes but the aircraft concerned was not a 747
it was an Airbus A310

http://aviation-safety.net/database/1994/940323-0.htm

Keith

"Keith Willshaw" wrote:


"Gord Beaman" wrote in message
.. .
"John R Weiss" wrote:

"Gord Beaman" wrote...

John, I recall that you're a qualified 747 F/E or Pilot so can
you tell me whether replacing aerodynamic trim of the tailplane
with fuel weight to reduce drag during cruise is still being
done?...I never seem to hear of it anymore, also what's the
proper nomenclature for that?

I'm a 747-400 Pilot.

Some 744s were delivered with fuel tanks in the horizontal tail. They
hold
10,000 Kg. I have not flown any airplanes with them installed, so I do
not know
any fuel management specifics for them.

While it may be possible to "passively" manage the CG by retaining the
tail fuel
as long as possible, I don't know if this is authorized. Also, AFAIK,
there is
no way to move fuel to the tail tank in flight -- once transferred down,
it
stays down.


It's really amazing what poor info one can gather on these ngs
isn't it?...I know for a fact that I've been told by those who
appeared to be authentic 747 aircrew that moving fuel to and from
the tail tank was used to replace aerodynamic fore and aft trim
to reduce drag on long cruise legs. Apparently this reduced the
stability so much that it could only be done with a serviceable
autopilot. And that it was only done during cruise, never for any
other phase of flight.

I understand that the basic reason for the Soviet Aeroflot
aircraft inflight breakup and crash several years ago was due to
the captain's son horsing the controls 'out of autopilot' during
this phase of flight and the subsequent violent motions prevented
recovery until some major structural failure had occurred.


Well yes but the aircraft concerned was not a 747
it was an Airbus A310

http://aviation-safety.net/database/1994/940323-0.htm

Keith



Ok...thanks Keith, in the report that I read the tail tank trim
was being used. Are you saying that the A310 doesn't use tail
fuel trim?...and are you familiar with this system?
--

-Gord.
(use gordon in email)

Gord,
Concerning the weight shift and CG movemnt to get better cruise economy. The
MD-11 has that capability and is used operationaly at Fedex. There have been
some problems with the system. The MD is the most unsafe modern transport
catagory aircraft in history.
We had one make a hard landing and we learned after the crash that the wing is
designed to fail before the landing gear does resulting in the wing coming off
and the plane coming to rest upside down.
There have been some problems with the fly by wire lag in the flight controls
that resulted in PIO during the landing. I don't know anything more about the
specifics on these problms but I guess I will learn when I transition to the
Mad Dog in a few years.
Sparky

"Elmshoot" wrotecom...
Concerning the weight shift and CG movemnt to get better cruise economy. The
MD-11 has that capability and is used operationaly at Fedex. There have been
some problems with the system. The MD is the most unsafe modern transport
catagory aircraft in history.
We had one make a hard landing and we learned after the crash that the wing
is
designed to fail before the landing gear does resulting in the wing coming off
and the plane coming to rest upside down.
There have been some problems with the fly by wire lag in the flight controls
that resulted in PIO during the landing. I don't know anything more about the
specifics on these problms but I guess I will learn when I transition to the
Mad Dog in a few years.

[Keeping a semblance of "military" in the thread...]

So, you're gonna bid the MD-[9]11 so you can git kilt in a civil airplane after
all those years in [E]A-6s?!? Can I have your flight jacket?

So, you're gonna bid the MD-[9]11 so you can git kilt in a civil airplane
after
all those years in [E]A-6s?!? Can I have your flight jacket?


John,
Now that you mention it, I must be nuts! Yep when I make the move I will be
chasing the $$ otherwise being in the right seat of the 727 has a lot of
benifits, although some how I spent another holiday away from home since I
ended up in Toronto for T-Day but my wife was very supportive. We just took a
one day delay. Heck after one deployment we had Christmas in Februaury.
Sparky

"Elmshoot" wrote...

Now that you mention it, I must be nuts! Yep when I make the move I will be
chasing the $$ otherwise being in the right seat of the 727 has a lot of
benifits, although some how I spent another holiday away from home since I
ended up in Toronto for T-Day but my wife was very supportive. We just took a
one day delay. Heck after one deployment we had Christmas in Februaury.

Well, bigger might get you the $$, but won't necessarily get you home when you
want... I spent T-Day in the right seat of a 747 between LAX and ICN. Somehow,
Australian ribeye at the Seoul Grand Hilton isn't quite smoked turkey. Come to
think of it, though, I was closer to my old Kamakura "home" than I was to my
current home...