TEDSKI From , joined Dec 1969, posts, RR: Posted (13 years 8 months 4 weeks 1 day 20 hours ago) and read 998 times:
Earlier today I was in CFM's website checking out the data on the various versions of the CFM56 and I am quite impressed. I know I have been bashing GE engines a lot, but this one is an exception. I like the CFM56-7 version that is on the new 737NGs. It has stronger components like the titanium fan blades which make me wonder why there is not a version of the CFM56-7 with more thrust over 35,000lbs that can be used on the Airbus A340-300E model instead of the CFM56-5?
Expratt From United States of America, joined Mar 2000, 311 posts, RR: 0
Reply 1, posted (13 years 8 months 4 weeks 1 day 20 hours ago) and read 969 times:
The CFM56 engine has already gone through several thrust increases, so there may not much left for additional thrust increases without encroaching on the necessary N1, N2, and EGT margins. The primary limiting factors if the existing design was retained would be fan speed, core air flow, and turbine inlet temperature. But if the fan, core, and/or turbines have to be changed, then it is a new certification program that is expensive and time consuming. Even if the engine does have additional thrust increase potential, GE may not want to invest in the development costs for a limited market.