Re: Engines (Was Re: Boeing in the WSJ)

From:         chuanga@wis.com (Andrew Chuang)
Organization: International Internet Association.
Date:         03 Nov 95 02:51:38 
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Karl Swartz (kls@ohare.Chicago.COM) wrote:
: >More RB211's than PW2000s on 757's? I didn't know that, and in fact would have
: >guessed the opposite. Actually, in casual obesrvations I've seen approximately
: >equal numbers.

I assume that you made your observations mostly in the States, then I would
say there are more PW2000-powered 757s.  Delta, NW, and UA accounted for
most of the PW2000-powered 757s.  In Europe, there are very very few 757s
with PW2000 engines.  Condor is the only European operator with a sizable
PW-powered B757 fleet.

: >Does anyone know the percentage split between the Rolls and
: >Pratt versions of the 757?

: In another post, Andrew recently said that the RB.211 has roughly
: 55-60% of the customers but more like 75-80% of the aircraft.  The
: difference comes from some of the largest fleets (Delta, Northwest,
: United) using Pratts.

Karl has inadvertently transposed the figures (it should be 55-60% of
the aircraft and so on).  The low-end numbers are my rough estimation
based on in-service 757s, the high-end ones are R-R's marketing numbers.
I think R-R has rounded up the numbers.

: Notably, one of the larger 757 customers switched from Pratt to Rolls.
: UPS started off with the PW2040 (a higher thrust engine for the higher
: weight freighters than the PW2037 usually used on passenger 757s) for
: their 757-200PF fleet.  After the first 35 aircraft, they switched to
: the RB.211-535E4 for future orders, with at least 15 Rolls-equipped
: aircraft now in service.  That's a pretty expensive change seeing as
: how it adds another engine type to their fleet.  (Their only other
: Rolls engines are Tays, on their re-engined 727s.)

Furthermore, I think the -535 and the Tays share very little hardware.
The PW2000 has better fuel efficiency and better reliability than the
-535, thus, it makes the switch even more mind-boggling.  Nevertheless,
mixed-engine fleet are not that uncommon outside the US.  The example
that I like to quote the most is Malaysia Airlines' B747 fleet.  MAS
has all the possible B747 powerplants under the sun, namely, the JT9D,
the RB211-524, the CF6, and the PW4000.

--
  H Andrew Chuang   chuanga@iia2.org