Sunday, June 1, 2008
Rotorcrat Report: Four Rotors Afloat?
Project Manager Alan Ewing said the industrial team is moving toward a prototype that can carry roughly 100,000 lb of fuel and cargo, in hopes of winning the Pentagon’s competition for a new joint heavy-lift aircraft.
Like its smaller cousin, the V-22 Osprey, the Quad Tilt-Rotor would be able to take off like a helicopter and fly like a plane. Like the Lockheed Martin C-130 Hercules airlifter, it would have four propellers and a lot of room for cargo. But unlike the C-130, it is designed to fly from the deck of an aircraft carrier. Ewing said the idea isn’t as far-fetched as it sounds.
"You think about an F-14," he said. "Its takeoff weight is about 68,000 lb. You put three of those in our parking spot, there’s a QTR."
The Bell-Boeing team has been testing Quad Tilt-Rotor designs and trying to figure out the "sweet spot" size for the aircraft. Ewing said the testing turned up some technical challenges, but no showstoppers. The design is based on the Osprey, but it’s almost half again as big.
As currently envisioned, the Quad Tilt-Rotor would be able to carry about 27 tons of cargo on a 250 nm roundtrip at 4,000 ft on a 95F day. Cruise speed would be about 275 kt, and the cargo bay would hold eight standard U.S. Air Force pallets, with room for another on the ramp. Ewing said it’s being designed with the Army’s Future Combat Systems combat vehicle family in mind. That means a big plane. If it gets built, the Quad Tilt-Rotor would have 50-55-ft-dia rotor blades, compared to the Osprey’s 38-ft-dia blades.
The Quad Tilt-Rotor was one of three proposals in line for a follow-on research contract under the U.S. Army-led Joint Heavy Lift program, but that has been eclipsed by the Joint Theater Future Lift program. That program is looking initially at an aircraft concept that could provide intra-theater lift for the U.S. Army, Marines, and Navy but also serve as a replacement for the Air Force’s fleet of C-130s and Boeing C-17s. Army and Air Force officials are just beginning concept definition of the Joint Theater Future Lift aircraft, and the program is not expected to start before Fiscal 2015 — By Rebecca Christie