Re: 757-300?

From:         ckd@eff.org (Christopher Davis)
Organization: Electronic Frontier Foundation Tech Central
Date:         25 Mar 93 00:08:04 PST
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HAC> == H. Andrew Chuang <chuang_hsin@ae.ge.com>
KS>  == Karl Swartz <kls@ohare.Chicago.COM>

 HAC> IMHO, the only 757 derivative that makes sense is a shortened version
 HAC> to fill in the gap between 737-400's and 757-200's (as well as to
 HAC> compete with A320's).

 KS> I noted last year that a shortened 757 seemed like a winner, to which
 KS> Greg Wright commented that Boeing had never successfully shortened an
 KS> aircraft.

Arguably, the 737-500 is a shortening of the -300; yes, yes, I *know* it's
the same size as the -200, but it's in the "new generation" 737 series.

Certainly that model seems to be doing well (or maybe it's just that
Southwest is buying them all :).

 KS> I still think the reasons for that are irrelavent to a "757-100" but
 KS> it got me thinking about the 757 further.  After doing some research I
 KS> was amazed at just how large an aircraft the 757 is.  Wing area is
 KS> about twice a 737 and MGTOW is nearly twice the heaviest 737.  In
 KS> these figures a 757 also greatly exceeds a 727-200 Advanced and has
 KS> tremendous range to boot -- over 4,500 miles.

The 757 is what I like to call a "teenager"--very gangly, doesn't look its
true size, has lots of spare energy...

 HAC> However, this will be feasible only if a derated PW2000 or RB211-535
 HAC> is available.

 KS> There really does seem to be a gap in engine offerings here.

True.  But if a derated engine did become available, wouldn't it have
really good MTBF numbers?  (Isn't that one of the big advantages of
derating?)  This would imply that a theoretical 757-100 with, say, derated
RB211s would have the dispatch reliability and time-between-maintenance to
serve in many of the current 727 "feeder" and "shuttle" roles.  (But can it
land at LGA?  If so, other advantages, especially with derating, could
include quieter engines and faster [therefore noise-abating] takeoffs.)

 KS> (Seriously, it's good to see someone from one of the engine
 KS> manufacturers contributing to the group.  Welcome!)

Agreed; the amount of real expertise here (both professional and `amateur')
is incredible.  I think a great deal of the thanks must go to our moderator
as well (and I'm not just saying this so he'll post my message :)

(Note also that I am *not* a real expert of either type, so I can't claim
that what I've said about derated engines is correct.  But I hope to be
corrected by those who *do* know, and learn therefrom.)
--
* Christopher Davis * <ckd@eff.org> * <ckd@kei.com> * [CKD1] * MIME * RIPEM *
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