Re: FT: Virgin interested in Superjumbo

From:         kls@ohare.Chicago.COM (Karl Swartz)
Organization: Chicago Software Works, Menlo Park, California
Date:         09 May 96 12:50:13 
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>Could anyone clear this up for me? Does the 747-600X use the same wing as
>the current (747-400) model or would Boeing develop a new wing?

It uses an entirely new wing.  There's a good summary of Boeing's
plans for the 747-600X (and 747-500X) starting on p. 32 of AW&ST from
February 7th.  It would have a new wing with a span of just over 242
feet, up from 211.4 feet on the 747-400 and -400F or 195.7 feet on the
older 747 models.  From the drawing, it appears that it will not have
winglets (consistent with Boeing's view, espoused during the design of
the 777, that they're not necessary for new designs) but if will need
a new wing/fuselage fairing.  New main landing gear (though still four
posts with four wheels each) together with the new wing will support a
MGTOW of up to 1,030,000 lbs, compared to 875,000 lbs (with 890,000 in
development) for the 747-400.  The nose gear gets bigger tires but is
otherwise unmodified.

The design also includes a taller, 747SP-type vertical tail, and a new
horizontal tail with an increased span of 87.5 feet.  Electrical
systems will be enhanced, with a 120 kVA generator on each engine.
(Gotta power all the in-seat slot machines, arcades, and whatnot!)
Upgrades to the air conditioning packs will support the higher loads
of the -600X or longer block times of the -500X.

The 747-600X fuselage is stretched 342 in. from the 747-400, including
a 220 in. plug just ahead of a relocated door 2, an 80 in. plug behind
the wing, and a 22 in. and 20 in. plug at the aft portion of the wing
root.  Range would be about 7,200 nm, comparable to the 747-400, with
a full payload.  Passenger capacity is 503, about 20% more than the
-400, plus about 14 metric tons of cargo in addition to baggage.

The 747-500X appears to be a shrunken -600X more than a stretched -400,
which makes sense since they share the same wing and other enhancements.
The foreward plug is reduced to 100 in. and the 80 in. aft plug is
eliminated entirely; the plugs in the wing root region are retained.
Total length would be 122 in. greater than the 747-400.  Range would
be in excess of 8,200 nm with a full payload of 444 passengers in a
"typical tri-class configuration."

Cruise speed is targeted to be M 0.855, similar to existing 747s.
(AW&ST reports M 0.86 for the 747-400, M 0.85 for the -300 and SP, and
M 0.84 for the other 747 models.  Apparently the extended upper deck
helps the -300 a bit, and the winglets add a bit more on the -400.)

The biggest point of controversy seems to be the cockpit.  Boeing
wants to keep the foreward section of the new models the same as the
747-400 to minimize costs.  Some airlines are asking for cockpits more
like that of the 777, possibly going as far as having a common type
rating.  Given Boeing's track record, I would bet on Boeing's capitu-
lation to the requests for the updated design.

--
Karl Swartz	|Home	kls@chicago.com
		|Work	kls@slac.stanford.edu
		|WWW	http://www.chicago.com/~kls/
Moderator of sci.aeronautics.airliners -- Unix/network work pays the bills