"Brian Whatcott" wrote in message
...
On Mon, 20 Jun 2005 20:42:54 GMT, Gord Beaman
wrote:

Brian Whatcott wrote:

On Mon, 20 Jun 2005 03:28:37 GMT, Gord Beaman
wrote:

Peter Clark wrote:

On Sat, 18 Jun 2005 08:07:11 -0400, Jack Davis
wrote:

On Sat, 18 Jun 2005 03:25:15 GMT, Gord Beaman
wrote:

Jack Davis wrote:

Huh? I've not flown a jet with a "small fuel tank in the tail". Am
I
missing something?

-Jack Davis
B737

Only on larger a/c Jack...747 have them (some at least). What I
find interesting is how few people seem to know much about them,
is it that they aren't used much now?...

I see. Obviously you can count me among the many who didn't have a
clue, and I used to fly 747s (-100 and -200).

FWIW, the 400 has them. I believe the 777 and A300 are similarly
equipped. From what I understand they pump to the CWT and help keep
things in the trim envelope when you're near MTOW and high fuel loads.

Yes, I'm certain that some (at least) of the 747's do have them
but this reason isn't what I'm talking about...it seems that the
Concorde article in this regard is all to do with the critical
fore/aft balance and to keep the CG where they want it for
different phases of flight and this post from Peter sounds
similar BUT it's not what I'm referring to which is using fuel
weight INSTEAD of aerodynamic trim to reduce drag for more
economical cruise.


Hmmmm...maybe I'm missing something: trimming near aft CG limit is
aero drag favorable in sub sonic transports

Brian Whatcott

Yes it is IF it's done by transferring fuel aft. This has to be
done ONLY at stable cruise though because it drastically reduces
the fore/aft stability and requires operation of the
autopilot...I understand that some a/c are unmanageable without
an autopilot in this condition due to the reduced stability.

IIRC a Russian airliner became unmanageable and crashed when the
Captain's teenaged son wrestled control from the autopilot while
the a/c was trimmed like this.

Is this what you meant Brian?


Well...I also recall hearing crew asking passengers to move on
account of unexpected cargo distribution. That was pre-take-off.

Brian Whatcott

Reminds me of a funny but true story involving a 727. No, a 727
does not have an HST. (only our 747-400 did )
As many may know, some model 727s require 'tow fuel,' which
is a minimum amount of fuel to prevent it sitting on it's tail when
the airstair is raised. Normally an easy operation at the terminal
gate.
In this case, a charter 727 for one of the '49ers away games
parked way over in our cargo area to offload the team to their
busses as they usually did. On this day they were having a problem
rounding up a fuel truck to upload 'tow fuel' so the word went out
over the radio for about a dozen or so bodies to substitute for fuel
during the short time it would take to reposition the aircraft.
Didn't take much persuasion since most of us are aware of how
well a #1 sports team is fed. In no time the front of that 727 was full
and the party had begun. I guess I should mention that our company
had a well published (and sometimes ignored) rule that an employee
caught raiding the galleys would be fired. :-(
It happens that the Ops. Manager heard the call go out as he was
driving around in his truck and decided to lend his substantial girth.
Last to arrive, as soon as he reached the top of the airstair it was raised
but as soon as he realized what was going on up front he realized
what a compromizing situation he was in. Being a good person
by nature he decided to stay aft instead of coming up front and
firing all of our asses! Even when somebody yelled out, "Hey George,
you're cancelling half of us out!"
As usual that ice cream and cake tasted gooood.