Re: A3XX vs B747-600

From:         kls@ohare.Chicago.COM (Karl Swartz)
Organization: Chicago Software Works, Menlo Park, California
Date:         25 Sep 96 13:40:12 
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>The 747-500/600 will have derivatives of existing engines, not brand
>new ones, unless someone at a later date decides to make one.

The Rolls-Royce offering (Trent 900) will be a derivative of the 777's
Trent 800, which itself is derived from the RB.211.

The other offering will be new though.  Pratt could have offered a
PW4000 midway between the 767's PW4060 and the 777's PW4084, but GE
had nothing since the CF6-80 is out of growth room and the GE90 is
way too large.  The PW4000 got nixed by Boeing, though, saying any
derivatives of existing engines would not meet their fuel burn and
noise goals, and Boeing pushed Pratt and GE into jointly building a
new engine.

This sounds like an attempt by Boeing to reduce their costs by having
only one engine offering, and to help their friends at GE who other-
wise would be out of the running for a second Boeing plane.  (GE also
has no engine for the 757, though they once proposed one.  On the
other hand, GE-Snecma is the sole source for the 737's engines.)  Of
course there's the Trent 900 which is being offered (by Rolls, at
least) despite being a derivative.

Anyway, AW&ST had an article on the GE-Pratt engine (the GP9000)
within the past several weeks.  GE will build the high-pressure parts
and combustor using a 90% scale GE90 core.  Pratt will build the fan
and low-pressure parts.

--
Karl Swartz	|Home	kls@chicago.com
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Moderator of sci.aeronautics.airliners -- Unix/network work pays the bills