Re: 747-100 SUD

From:         kls@ohare.Chicago.COM (Karl Swartz)
Organization: Chicago Software Works, Menlo Park, California
Date:         09 Nov 95 02:19:09 
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>What is involved in stretching the upper deck ? Doesn't this require some
>heavy duty structural changes ?  Doesn't this change the centre of gravity
>of the aircraft compared to the location of the wings ?

As far as I know, the differences between a late -200B and a -300 are
pretty localized, so it can't be too huge a modification.  The CG may
not change all that much because a signifcant portion is far enough
back to be over the wing.

>As well, what is the economic rationale of spending large sums of money
>to modify an relatively old aircraft to add a few more seats (8 to 10 ?)?

As far as I know, the only aircraft that were modified were done when
the -300 first came out, so they were modifying fairly new aircraft.
It probably wouldn't be economical now.  As for seats, roughly double
the number upstairs -- before increasing pitch, United got five rows
upstairs on a late -200B (they only have two; yes, I know their other
-200Bs and the -100s only have four rows) and effectively ten rows on
a -400 (which has the same upper deck as a -300 or an SUD).  In a high
density config, I could see that being another 40-50 seats or more.

>Or do those modifications also include the upgrading of engines and cockpit
>to enhance the fuel consumption figures to bring them up to par with more
>recent aircrafts ?

Some of the mods might have included MGTOW increases, which could
include upgraded engines.  However, as noted above, these aren't
recent upgrades so it wasn't a matter of updating them.

--
Karl Swartz	|Home	kls@chicago.com
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