CFM International's mid- and long-term product development strategy for the CFM56 engine hinges on the outcome of a series of key TECH56 technology upgrade programme tests. These will take place within the next few weeks for the swept fan blade design, dual spool rig, high- pressure compressor and turbine, combustor and brush seals.

The test series is the halfway point for the TECH56 effort, which was launched in 1998 to ensure a viable future for the turbofan in the face of new requirements and the threat of growing competition from rivals. One of the earliest TECH56 tests was the "chevron" nozzle, which has been tested at full scale in 1999 on a CF6-80C2, and showed a 3dB improvement in exhaust noise levels.

Test results are being fed directly into product development strategy studies under way with Airbus Industrie and Boeing, says Bill Clapper, General Electric executive vice-president and CFM CFM56 project general manager, . "I think the recommendations will come out in the first half of next year. My bet will be an improvement to the product line and a new engine in the long term."

Validation tests of the wide- chord, swept-fan blade design culminated in a fan blade-out test and were completed in early March. They indicate the potential for a 1.5% fuel consumption saving, as well as a 4-6% thrust growth for the same diameter. "We could go back to the -7B [on the Boeing Next Generation 737] and make it a 29,000-29,500lb thrust [130-131kN] engine. It is the same story for the A320 family," says Clapper.

Validation tests of an advanced six-stage high pressure compressor will start this month. "This would be the foundation for a new engine," says Clapper.

Source: Flight International