Airbus and CFM International will begin delivering A320-family aircraft equipped with a performance upgrade developed from the Boeing 737's CFM56-7BE Evolution engine at the end of this year.

The improvement, which CFM expects will offer a 0.5% gain in fuel burn and lower maintenance costs, comprises manufacturing changes and hardware changes to the core. It will become standard on the A320's CFM56-5B/3 engine once introduced, says CFM's marketing general manager Bill Brown.

"The objective of the [performance improvement package] is an SFC reduction from added aero-efficiency and a maintenance-cost benefit because there are fewer high pressure turbine blades," he says.

Brown says that there are two significant elements to the core changes: hardware modifications in the turbine and minor production changes to the fan and compressor blades.

"The significant changes are new high-pressure turbine blades which have improved aero-efficiency, a new HPT disc and new forward outer seal. The manufacturing process for fan blades and compressor blades and vanes has been improved to tighten tolerances and improve surface finishes."

The improvements also enable CFM to match the life-limited part (LLP) cycles of all core modules. "The entire core - compressor and turbine - is now at 20,000 cycles. This matches the time-on-wing better so you're not removing engines for LLP life as often," Brown says.

The upgrade was flight-tested by Airbus during January and February, with 26h of trials flown during 11 flights, says CFM.

"We'll be going into production at the end of this year and then we'll see Airbus change its performance summary to reflect the 0.5% improvement in the orange book once it validates this," says Brown.

The package will then become standard and available for retrofit during overhaul. "We'll be offering some incentives so the new hardware will probably be available for less [than older components]," he adds.

It "closes the gap" to the rival International Aero Engines V2500 in fuel burn for an engine "normalised" for deterioration, says Brown, and further improvements could follow: "We're always investing in advancing in 3-D aero, but what the next upgrade is will depend on how many more sales of this engine are going occur because of the introduction of a new aircraft and re-engining."

Source: Flight International