Re: GE90 Engines

From:         chuanga@iia2.org (H Andrew Chuang)
Organization: International Internet Association.
Date:         08 Jul 95 15:01:53 
References:   1 2 3 4
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In article <airliners.1995.975@ohare.chicago.com>,
Karl Swartz <kls@ohare.Chicago.COM> wrote:
>
>That doesn't make sense -- the three shaft design has always resulted
>in a weight penalty for the RB.211, though RR has claimed that the
>increased efficiency of the design more than compensates for the added
>weight.  From AW&ST, here are the weights of the GE and PW engines for
>the MD-11:
>
>    GE CF6-80C2D1F	9,634 lbs
>    PW PW4460		9,400 lbs
>
>The RB.211-524H, used on the 747 and 767, is about the same thrust,
>and weighs 9,499 lbs, only 135 lbs lighter than the GE engine and a
>bit *heavier* than the PW engine.
>

First of all, to compare with the RB.211-524H, you should really use the
firgures of GE's CF6-80C2BxF and Pratt's PW40[5,6]x (for Pratt's number,
it doesn't make a difference, because AW&ST listed them all at 9,400 libs).
The Trent 600, which was cancelled, would have been the equivalent of
-80C2D1F or PW4460.

The previous poster was correct to say the RB.211 on the L-1011 were
lighter than the comparable GE or P&W engines.  The reason why the
-524G/H is heavier is because of the "integrated exhaust nozzle" design
(GE/SNECMA called it long-duct mixed-flow design which is used in the
CFM56-5C on the A340).  The Trent 800 which is used on the B777 does not
have the integrated exhaust nozzle, and the Trent 800-powered B777 is about
2,000-3,000 lb lighter than the PW4084-powered B777 per aircraft, and
about 6,000 lb lighter than the GE90-powered B777.  Nevertheless, the
R-R engines always seem to be less fuel efficient.

--
  H Andrew Chuang   chuanga@iia2.org