CFM International will announce at the show that it is studying an upgrade plan for the CFM56-3 engine that could give operators of almost 2,000 Boeing "Classic" 737s improved fuel efficiency, lower maintenance costs and longer on-wing life.
The core of the kit, which could be launched in the next few months, is based on three-dimensional aerodynamic design improvements to the high-pressure compressor and turbine originally fitted on the -5B engine used in the Airbus A320 family.
CFM says the hardware used in the test was from the -7B version used in the Next Generation 737.
CFM also reveals that late last year it secretly completed a 95h demonstration programme to "evaluate the potential for an upgrade kit" which could be certified within 24 months if launched. "We're still working through the data," adds the company, which says there are 3,975 CFM56-3s powering 1,987 737-300s, -400s and -500s.
It says the demonstration showed "there are no technical limitations to this programme and it met all pre-test expectations". The expected benefits of the kit will include an extra 15íC in exhaust gas turbine margin, which will translate into "significantly" more time on wing.
On average, CFM56-3 engines stay on wing 14,000h before removal for an initial shop visit and about 10,000h before overhaul. The engine manufacturer, a joint General Electric-Snecma company, also expects to see an improvement of up to 1% in specific fuel consumption.
Turbine upgrades also being evaluated including new nozzle, blade and shroud materials, as well as improved cooling. These changes would result in longer component life, says the company, with up to 50% lower scrap and repair costs.
• CFM's TECH56 project, which is paving the way to the next generation of CFM56 engines, is moving toward tests of a second-build, new six-stage high-pressure compressor design in the third quarter.
Results of the recently completed first test series have been "very promising", says CFM, which is also about to begin first tests of a new dual-spool high- and low-pressure turbine design.
Additional dual-spool tests, including a counter-rotating turbine design, are set for later this year. Tests of the low-emissions, TAPS (twin annular, pre-swirl) combustor are also imminent, the company says.
Source: Flight International
