Bell has been awarded two study contracts by the US Defense Advanced Research Projects Agency (DARPA) to determine whether a Quad Tiltrotor (QTR) demonstrator should be developed.
In November, Bell is to provide DARPA with a study detailing the technology needed to evolve the Bell Boeing V-22 Osprey tiltrotor into a 20t-class QTR. Addressed in the report will be an uprated drive system and aircraft weight reductions.
Bell's director of tiltrotor business development, Dick Spivey says General Electric, Pratt & Whitney and Rolls-Royce powerplants emerging from the Joint Turbine Advanced Gas Generator research programme and growth models of existing R-R designs are the QTR engine options.
Under the second contract, Bell has built a QTR hover download model to allow a year of flight testing to start late this year.
DARPA will shortly decide whether two windtunnel models will be built, one of which will be an aeroelastic model to test interference between the front and rear rotors. Windtunnel work will run to the end of next year. At that point, says Spivey, DARPA will have enough data to decide whether to build a QTR demonstrator that would fly in 2006.
The QTR would use V-22 components, taken off the Osprey production line, mated to an enlarged fuselage and new landing gear, wings and flight control system. Spivey says Bell would like to build two QTR demonstrators.
Meanwhile, Bell is seeking NASA funding for complementary research to convert the company's Eagle Eye tiltrotor unmanned air vehicle to a high-speed folding-proprotor testbed.
Source: Flight International
