Re: Concorde Question?

From:         Alex Lee <alexlee@MIT.EDU>
Date:         20 May 94 01:58:40 
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>The longer-range Airbuses as well as the 747-400 (maybe the MD-11 too,
>though I'm not sure) also use it for balance.  They can have fuel tanks
>in their horizontal stabilizers that help reduce drag at cruise (hence
>improve range) by moving the CG back, permitting reduced elevator trim.

I talked to a 747-400 captain a while back, and asked him if they 
transfer fuel in flight to the tank in the stabilizer to reduce trim 
drag.  The answer, to my surprise, was NO.  He said unlike the MD-11's
and the airbuses, the 747-400s only use the stabilizer tank to store 
fuel, not to move the CG to reduce trim drag. Anyone out there who can
verify that?

On a side note, the captain also told me that when flying the 747-400
Combi versions, they can't burn all the fuel they have in the center
tank.  Because the Combi is tail-heavy due to the cargo load, fuel has
to be used to balance the plane.  Therefore, the range is reduced. 
That is very interesting.

-Alex