Date: 16 Sep 99 16:42:58 From: firstname.lastname@example.org Organization: Deja.com - Share what you know. Learn what you don't. References: 1
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In article <airliners.1999.973@ohare.Chicago.COM>, JF Mezei <email@example.com> wrote: > A recent post mentioned the R&D mega expenditures required to produce > the engine for the next 777 which is a big reason only one manufacturer > will build one. > > I am starting to wonder if the extra cost of pushing the "state of the > art" limits to get the required performance on a twin is really worth > all the effort ? > > Are we not getting to a point where conventional jet engines are > reaching the top of the bell curve and any improvements will cost more > and more ? > > On the other hand, by using 4 engines (or even 3), it allows you to use > much more conventional technology which is not only cheaper for R&D but > has greater market and hence more competition. Actually, your understanding of the situation is not entirely correct. Let me use GE's earlier involvement in the A340X program as an example. When Airbus was studying what eventually became the A340-500/600, Airbus signed a six-month exclusive engine study with GE. At the end of the engine study, GE concluded that they would have to spend US$1b for a brand new engine. GE did not think the A340-500/600 market would be large enough to justify the US$1b investment, and Airbus was unwilling to foot part of the cost. Hence, GE walked away from the exclusive deal (and Rolls-Royce won the eventual competition with P&W mostly because P&W insisted on exclusivity). On the B777X, GE is expected to spend US$500m for the derivative engine development. However, GE is also going to split half of the airframe development cost with Boeing (around US$500m for GE) in order to secure the exclusivity right on the airframe. Thus, you can see, it's not more expensive to develop a big twin engine. However, the 115K-lb thrust engine is like to have only one application in the near future. Sent via Deja.com http://www.deja.com/ Share what you know. Learn what you don't.