GRAHAM WARWICK / WASHINGTON DC
Changes to the newest member of the family include a swept-blade fan and low-emissions combustor technology
The latest addition to Pratt & Whitney Canada's PW300 turbofan family, the PW307A, features new swept-blade fan and low-emissions combustor technology.
The engine, selected to power Dassault's Falcon 7X business trijet, will be developed using a methodology intended to increase maturity at entry into service.
The PW307A is a 6,100lb-thrust (27.1kN) growth version of the PW306 powering the Fairchild Dornier 328JET regional jet and Gulfstream 200 super mid-size business jet. It will also power the mid-size Cessna Citation Sovereign when it flies early next year.
P&WC chief executive Gilles Quimet says Dassault's performance targets for the Falcon 7X required an engine "between the PW306 and the PW308". The latter is the largest member of the PW300 family, a new-centreline engine developed to power the Falcon 2000EX large business jet and the super mid-size Raytheon Hawker Horizon.
Changes introduced on the PW307A include the swept fan, increased core airflow, low-emissions combustor, increased turbine capacity and a more efficient exhaust mixer. The result, says Quimet, is an engine with "extremely high performance, low fuel burn, emissions and noise, under the most stringent regulations by a substantial margin".
As a risk-sharing partner in Falcon 7X development, P&WC is responsible for the integrated propulsion system. This includes the nacelle and thrust-reverser to be supplied by European venture Macchi Hurel Dubois. Certification of the PW307A is scheduled for the end of 2004 and 7X certification is planned for the first half of 2006.
Swept-fan technology is under development for P&WC's PW625 small turbofan - the demonstrator of which completed its first run last week - and is running on a PW308 experimental engine, says Quimet. The Canadian company has completed critical birdstrike tests to verify the structural integrity of the design, which he describes as "a step forward for turbofans" in terms of efficiency and noise. The combustor will use technology being developed with sister company Pratt & Whitney, which allows better control of internal temperatures "and the lowest possible NOx [oxides of nitrogen] emissions", he adds.
P&WC will apply its new mature engine reliability at service introduction (MERSI) methodology to development of the PW307A. Under MERSI, "we do far more instrumented testing early on to determine the actual physical environment in which the engine operates, then design tests that expand the environment and test the engine to failure, to really understand the margins", says Quimet. The goal is to identify and fix by-service-entry problems that usually emerge in the first few years' use.
Source: Flight International
