Bell Helicopter Unveils Next-Generation Tiltrotor
Bell Helicopter unveiled its next-generation tiltrotor on April 10 at the Army Aviation Association of America (Quad A) annual convention in Fort Worth, Texas. Bell intends to enter the V-280 Valor in the U.S. Army’scompetition for a joint multi-role (JMR) helicopterand is committed to building and flying a prototype by or before 2017, said Chris Gehler, Bell’s business development manager for future vertical-lift programs.
The V-280 is designed to carry 11 fully outfitted troops, fly up to 800 nm at a maximum speed of 280 knots and satisfy the Army’s requirement for aircraft operations at up to 6,000 feet at 95 degrees F. Estimated mtow of the V-280 is approximately 30,000 pounds and the aircraft will be configured for utility and attack missions and feature composite construction. Unlike the Bell-Boeing V-22 Osprey currently in service with the Marines and the Air Force, the V-280 features six-foot-wide sliding side doors and a V tail. It does not have an aft ramp door as on the V-22 and will feature an engine different from the Rolls-Royce AE1107Cs on that aircraft.
Another difference is that the engines on the V-280 will not tilt as they do on the V-22. Rather, the gearbox enables the prop-rotor to rotate. “Separating the engine and gearbox out of the same nacelle reduces complexity and increases maintainability. We developed a new transmission piece and a 90-degree gearbox that enables those engines to remain in a fixed position. Just the pylon with the prop-rotor rotates and that eliminates the ground heating and exhaust thrust of the V-22,” Gehler said. While the design eliminates the 1,700 pounds of thrust attributable to engine exhaust on the V-22, that will not adversely affect the V-280’s performance, he said. Gehler noted that the V-280 shares much of the advanced systems architecture, including fly-by-wire, of theBell 525 Relentless super-medium twin commercial helicopterannounced last year.
Bell plans to fund design of the V-280 and construction of a prototype with its suppliers and a yet-to-be named major partner. The JMR program is designed to field a common replacement for helicopters that are currently the backbone of U.S. military aviation, including the AH-1Z Cobra and AH-64D Apache gunships, CH-47F Chinook, OH-58D Kiowa, UH-60M Black Hawk and UH-1Y Huey. Production of the winning design could begin in 2025.
The competition includes several phases, and entries for phase one closed in March. The Army is looking for a design that “greatly surpasses” the performance and reliability of current helicopters. The potential spoils from JMR are huge: in 2011 the U.S. Congressional Budget Office estimated the cost of the program at $57 billion. In addition to Bell, other competitors include AVX Aircraft and a Boeing-Sikorsky partnership.