AlliedSignal is "committed" to development of all new turbofans in the 18-36kN (4,000-8,000lb)-thrust range, providing a next-generation powerplant for business aircraft and small regional jets.

AlliedSignal engineering vice-president Carl Schopfer, revealing Ìrst details of the AS900, says: "We are committed to the programme, but we will be looking for risk-sharing partners. We are talking to a number of people at the moment." Development cost is estimated at roughly $300 million.

Although specific technical details of the engine are not being announced, the AS900 family will have advances in materials and design technology. It will also have a reduced parts count by using design features such as integrated blade-disks, or blisks. "We are also aligning the design with advances in our manufacturing technology to make it more cost competitive," adds Schopfer.

"The design does a couple of things: it protects the position in the larger business-jet arena at the upper end of our TFE731 range. Secondly, it allows us to develop a range of products for the light regional jets," Schopfer says. AlliedSignal says that the first likely launch customer will be a business-aircraft manufacturer. Schopfer says that the first version could be developed "in a 36-month timeframe".

The initial family is expected to consist of the AS904, AS906 and AS908, with possible growth versions to be added later.

The AS908 version, if launched, would form the basis for AlliedSignal's bid to power the Fairchild Dornier 50-seat 528JET. The US-based airframer is believed to be encouraging AlliedSignal's efforts to launch the new engine as it believes it would give the 528JET a significant edge over established 50-seat regional jets

AlliedSignal has outlined details of the AS108 engine which it is offering against the Pratt & Whitney Canada PW308B and Allison AE3007 to power the proposed Embraer EMB-135. To meet Embraer's tight development timescale, which calls for entry-into-service at the end of 1999, AlliedSignal is deriving the AS108 directly from the LF507.

This will be fitted with a new fan, low-pressure turbine and several materials and aerodynamics changes in the core. "For all intents and purposes, this is a new engine," says the company. The final definition of the AS108 is still in design, but includes the possibility of a wide-chord fan.

Source: Flight International