Bell Helicopter is negotiating with the US Office of Naval Research (ONR) to fund a windtunnel test of the X-Hawk vertical-lift aircraft, designed jointly with Israel's Urban Aeronautics.
Using a pair of ducted fans, the X-Hawk is designed for operations in urban environments where exposed helicopter rotors pose safety risks. Bell is working to secure $10 million in ONR funding to test a one-third scale model of the X-Hawk for windtunnel testing in 2008, says John Tatro, Bell's director of advanced concept development. Fancraft technology developer Urban flew a proof-of-concept vehicle in 2003, and in 2005 windtunnel-tested a one-tenth scale model of the X-Hawk.
Tatro says the Fancraft concept is at the same stage that tiltrotor technology was before Bell flew the XV-15 demonstrator in 1977. The XV-15 led to the Bell Boeing V-22 Osprey tiltrotor transport, which is scheduled to enter service next year. Bell and Urban want to fly a full-scale demonstrator of the X-Hawk by 2010, which would allow system development and demonstration of a military Fancraft to begin by 2014.
Powered by two 1,820shp (1,357kW) LHTEC CTS800 turboshafts driving fore and aft shrouded rotors for lift and control as well as aft-mounted ducted propulsors, the X-Hawk has a cabin similar in size to that of a Bell UH-1 Huey, Tatro says, but is only 4.3m (14ft) wide compared with the 7.9m rotor diameter of the US military's smallest helicopter, the Boeing MH-6 Little Bird.
If demonstrated successfully, Tatro says, the X-Hawk would provide an ability to operate within urban canyons that does not exist today. The major challenge, he says, is whether the X-Hawk can be made light enough to have a useful payload and viable performance.
Source: Flight International
