B744 tailplane fuel

[capt stalingrad]

Hi all

Would some one care to elaborate on whether or not the 744 has a capacity to carry fuel in the tailplane.

If so, how much and under what circumstances is it used.

Cheers. CS

[TopBunk]

Yes, it is an option.

From recollection it holds about 8.5 tonnes of fuel (about the same as the wing on a 737-200!).

For take off the engines are fed by their respective wing tanks, shortly after take off fuel is fed to all engines from the centre wing tank. Once sufficient fuel has been used from the CWT the Stab tank fuel is pumped forwards into the CWT. There are 2 pumps, and if for some reason you can't pump it all forward, there are some very severe consequences due to Cof G implications - you cannot use CWT fuel nor jettison fuel. The wings hold 110 tonnes, the CWT 55 tonnes. You must land with minimum 15 tonnes in inboard wing tanks to maintain CofG limits. This could mean you land with, in the worst case, 55 tonnes (CWT + Stab tank) + 15 (or more) tonnes (wings). This is quite likely to mean landing above max weight by about 30 tonnes, with a Vref of about 170 kts.

Normally it is used only when you load over about 125 tonnes of fuel for the flight (about10.5 hrs with reserves) and can be used for trim reasons. Obviously you don't NEED to put any in until the wings and CWT are full.

[NSEU]

"For take off the engines are fed by their respective wing tanks, shortly after take off fuel is fed to all engines from the centre wing tank."

I think you'll find that with fuel in the CWT(Center Wing Tank) and flaps extended for takeoff and initial climb, the CWT will feed the #1 and #4 engines and the inboard wing tanks will feed their respective (#2 and #3) engines. With flaps up, the CWT feeds all engines until, as you say, the CWT quantity reaches the point where fuel can be transferred from the HST (Horizontal Stabilizer Tank).

The HST holds about 3,300 US Gallons (22,110lbs / 12,492litres / 10,029Kg).

Rgds.
NSEU.

[Harry G]

In our company on the -400 when more than 150 ton of fuel is required the HST is used.

If any HST fuel is required a minimum of 3,200kgs must be loaded.

During cruise when the Centre Wing Tank (CWT) qty reduces to 36.5t we transfer fuel from the HST to the CWT.

For info the CWT holds 64,973 lts / 52,162 kgs.
All up the -400 can be loaded up with 216,390 lts / 173,740 kgs.

[Kaddyuk]

Yup, as mentioned above they are an option.

In VS they are installed on ROM, ROS, ROY, LIP and GAL. The LGW 744's who were ordered by Alitallia but delivered to VS.

The tank is there but never really gets used. The tank is not present on any of our LHR jumbos.

:ok:

[kuobin]

AS I KNOW,MOST OF PASSENGER AIRPLANE DOES HAVE TAILPLANE TANK,WHILE FREIGHTER DOES NOT.:O

[TopBunk]

NSEU

Just checked (belatedly:O ) through the tech manual and you are of course correct ... to the kilogram!

Haven't flown the delightful beast for about 3 years, and was going from memory ... was sort of right!

Hoping to refresh my memory on a (re)conversion course in the next 18 months;)