Honeywell AS900 Delayed, But Improved

Certification of the AS907, the turbofan powering the new Bombardier BD100 Continental, has been rolled back to second quarter 2002 from September 2001 to incorporate durability and maintainability improvements wanted by operators and airframe manufacturers, according to Michael Redenbaugh, Honeywell's VP and GM AS900 program. AS977, four of which are fitted to the BAe Systems Avro RJX, also has been delayed to first quarter 2002.

"We are continuing to make improvements to the engine closer to maturity prior to entry-into-service," Redenbaugh explained. A fan stator with individually replaceable blades and better combustor cooling are two such improvements that pushed back the certification dates. The pay-off is lower life cycle costs and easier maintenance, Redenbaugh said.

The improvements are not delaying delivery of flight test engines to Bombardier and BAe Systems. The RJX has completed 30 test flights and a second set of AS977 flight test engines has been delivered to BAe Systems. The AS907 engines fitted to the Continental have undergone ground runs in preparation for the aircraft's first flight, slated for mid-summer.

AS900 engines have a 34.2-inch fan and a 4.2:1 bypass ratio, making them good airport neighbors. All compressor and turbine discs have a 25,000-cycle design life when the engine reaches maturity.

By Fred George