Showing posts with label Son of Osprey. Show all posts
Showing posts with label Son of Osprey. Show all posts

22 Oct 2011

‘Son of Osprey’ to Replace All Army Copters

The V-22 Osprey tiltrotor flown by the Marines and Air Force crashes or burns much more often than the military cares to admit. But that hasn’t stopped Osprey-maker Boeing from pitching a new tiltrotor for an ambitious Army program aimed at replacing almost everything the ground combat branch flies … with a single aircraft design.
That’s potentially thousands of new tiltrotors, which take off vertically like helicopters but fly fast like airplanes, thanks to their rotating engine nacelles — but which are also vulnerable to dangerous aerodynamic phenomena and, in the V-22’s case, have been plagued by engine problems.
By continuing to invest in the V-22, the Pentagon is doubling down on a risky bet. If Boeing’s “son of Osprey” gets the greenlight for the comprehensive Joint Multi-Role program, the military will be going all in. But a lot could change between now and 2025, when the first of the new rotorcraft is (loosely) scheduled to enter service. And there’s reason to believe a new tiltrotor could avoid the pitfalls of the Osprey’s design.
Boeing showed off some preliminary artwork of their Joint Multi-Role tiltrotor at an Army confab in Washington, D.C., last week. The art shows a small, sleek scout version and a larger cargo model. “Those images are nothing more than artist concepts and not necessarily associated with a specific design philosophy,” Boeing spokesman Chris Haddox told Danger Room. “The work is just getting underway.”
All the same, the Boeing concept shows apparent improvements over the V-22. Specifically, simpler wings and better rotors.
To fit aboard the Navy assault ships that carry Marines into battle, the V-22 had to have a wing that could fold back along the fuselage — at the cost of extra weight and complexity. The Osprey’s rotors also had to be smaller than ideal for a 25-ton aircraft, forcing the engines to work harder and run hotter.
Over the years, engineers have proposed solutions to this problem. Farhan Gandhi, an engineer at Penn State University, proposed a telescoping rotor blade that would automatically increase in length during a tiltrotor’s helicopter mode, increasing its lifting ability. One retired V-22 engineer told analyst Lee Gaillard that replacing the V-22’s three-blade rotor with a new, five-blade model (.pdf) would boost performance. In the end, Boeing opted for tweaks to the V-22’s software to squeeze every last bit of performance out of the existing design.
Boeing’s conceptual future tiltrotor seems to avoid these half-measures by incorporating bigger rotors from the outset on the scout model, and twin rotors — that is, two sets of blades on each nacelle — for the cargo version. An Army tiltrotor could probably also skip the folding wing mechanism, as seems to be the case in the artist’s renderings. The result could be a safer, better-performing tiltrotor than the troubled V-22.
Photo credit: US Air Force
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