Tests pass 40h mark as manufacturer prepares to deliver first powerplant to Northrop
Pratt & Whitney has started ground tests of its F100-220U engine for the Northrop Grumman X-47B Joint Unmanned Combat Air System (J-UCAS) demonstrator, and plans to use the experience to develop its preferred propulsion solution for the emerging US Air Force medium-range bomber requirement.
The current tests, which have already passed the 40h mark, are being undertaken at P&W’s West Palm Beach site in Florida and will culminate after around 100 ground test hours with the delivery of the first engine to Northrop. This will be installed in the first X-47B in the second quarter of 2006 ahead of flight tests from mid-2007.
The -220U is a “slightly modified” version of the F100-220E turbofan without the augmentor, or afterburner. “There is no augmentor on this application, but eventually for an operational vehicle we will have to offer a unique propulsion system,” says P&W vice-president military development programmes Bennett Croswell. This is likely to require capabilities residing in both commercial and military engines, he adds. “We will need an engine that can provide a lot of thrust in a buried installation, which needs a fan that is more like a military fan. But we need a lot of loiter time and range, so we will need a core with good specific fuel consumption characteristics,” says Croswell.
Evaluation of the engine, which could power a potential vehicle that brings together the USAF’s future bomber needs with the J-UCAS, will parallel flight-test work on the F100-powered X-47B, he adds. The future engine will require a low-pressure spool and fan designed for high take-off power, together with the capability to generate sufficient on-board electrical power. “We’re working on an integrated approach for thermal and power management and we will have the opportunity to do even more than we did on the [Lockheed Martin F-35] Joint Strike Fighter,” says Croswell.
Several commercial cores are being considered as the basis for future studies, ranging from the PW6000 to the all-new centreline engine being proposed for Bombardier’s CSeries airliner. Assuming a CSeries go-ahead from September, Pratt & Whitney Canada plans to launch a $1 billion development effort based on its PW800 technology demonstrator, to be aimed at the 16,000-22,000lb thrust (70-98kN) range.
GUY NORRIS / LOS ANGELES
Source: Flight International
