Re: Boeing considering ultra-long range 747-200X

Date:         15 Nov 97 16:24:42 
From:         mweber@t140.aone.net.au (James Matthew Weber)
Organization: Customer of Access One Pty Ltd, Melbourne, Australia
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On 05 Nov 97 23:41:56 , kls@ohare.Chicago.COM (Karl Swartz) wrote:
>The 747-200X moniker suggests that the proposal would use the small
>upper deck of the 747-400F (same size as the 747-100/200) with the
>airframe weight reduction allowing the increased range.  (According
>to www.boeing.com, the MGTOW and fuel capacity of the 747-400F is the
>same as the passenger version, so the freighter airframe doesn't seem
>to offer any benefit in that regard.  What happened to the freighter
>having a stronger wing that boosted it from 875,000 lbs to 920,000 lbs
>MGTOW?)

The Flight International Article quotes the MGTOW as 397,000 Kg, which
is 875,000 pounds. This is the standard for  passenger and Combi
-400's. Aviation Week's 1997 Aerospace Source book quotes the MGTOW on
the 747-400F as 811,000 pounds however, but MLW on the 400F is 660,000
pounds versus 630,000 pounds on the standard -400.

The proposal  (according to Flight International) involves an increase
in MGTOW, from as little as 399,500kg (which is a whole 5500 pounds)
up to 413,100kg, which is about 920,000 pounds.  The 400F has an empty
weight advtange over a passenger -400 of about 35,000 pounds. Couple
that with the  max imum increase in MGTOW, you have a choice between
up to about 3.5 hours extra endurance or 2 hours more endurance with
30,000 pounds more payload.

This would put ultimate endurance at 17-18.5 hours with reasonable
loads.

>the increased competitive threat posed by the A340-600.  The smaller
>A340-500 still boasts the greatest range.
>
>  model     pax (3-class)  range (mi/km)
>  -----     -------------  -------------
>  747-400        420       8,380 / 13,480
>  747-200X     355-380     9,200 / 14,800
>  777-200IGW   305-328     8,600 / 13,845
>  A340-600       378       8,390 / 13,500
>  A340-500       313       9,570 / 15,400

I am compelled to point that early examples of aircraft almost never
meet performance guarantees. There are enough differences in how the
loads and ranges are calculated that it hard to be sure if the
747-200X really has shorter range than the A340-500. It may well be
academic, because I can't think of any routes that are longer than
14,800km and shorter than 15,400km.

I'd add that Flight International says :
 'The new 747 will offer range inthe order 14,800km ... '
That sounds to me to be not very definitive, and probably won't be
until the MGTOW issue is settled. Depending upon what happens there,
my thumbnail caculation says the range could be as little as
9000miles/14,400km to as much as 10,300miles/16,500km. Depends upon
how much the MGTOW is increased, and how much you use of that for
payload and how much for fuel.

In any event the aircraft is clearly not adequately defined  at this
stage to make  such a comparison very meaningful.

The 413,100kg upper limit is apparently derived from the need to alter
the tail assembly if you exceed that level (again according to Flight
International).

My views anyway