PAUL LEWIS / SEATTLE
First two demonstrator vehicles have 50% more power than required, so lower-thrust versions are being pursued
Boeing is searching for an engine to power the projected production version of the US Air Force's planned Unmanned Combat Air Vehicle (UCAV), together with a third X-45 demonstrator, as the company works to finalise software to clear the first two completed test vehicles for flight tests in December.
Engine manufacturers have been responding to a Boeing request for information on a 5,000lb-thrust (22kN)class powerplant for the UCAV Operational System (UOS). The first two X-45A UCAV Demonstrator Systems (UDS) will be powered by the Honeywell F124, which has about 50% more power than is required, according to Steve Berg, Boeing Phantom Works UCAV technology insertion manager.
Potential bidders include Honeywell, with either a refanned AS900 or lower-thrust F124, and Pratt & Whitney Canada with the PWC305. Rolls-Royce is understood to be considering a derated AE3007 or possibly a new centreline powerplant under study for the civil regional and business jet markets.
Boeing is in the initial phase of refining the UOS and before the end of the year "expects to have an idea what engine to go with", says Berg. The company recently received an additional $50 million to advance design work on the X-45B during the on-going initial UDS phase. The USAF has earmarked phase two funding to begin building the third demonstrator in 2004 for a planned first flight in late 2005.
This was necessary to keep the UCAV programme on schedule due to delays to X-45A flight testing. "Both vehicles are complete, we're just waiting for software to get off the ground," says Berg.
The X-45B will be a 80% design representative vehicle, including low observability features, a new engine and possibly a synthetic aperture radar. The USAF is hoping to field an initial 16 Block 10 UOS vehicles by 2007.
Source: Flight International
