Wednesday, April 11, 2007

Boeing PelicanA concept

Boeing PelicanA concept aircraft currently under development at Boeing’s Phantom Works Research and Development unit might be the largest airplane to ever fly, but it won’t set any altitude records. Its called the Pelican and it would have a normal cruising altitude of only twenty feet because it uses the concept of ground effect to achieve lift.
Performance specifications say this ground effect vehicle (GEV) will have a wingspan of 150 meters and be able to carry up to 1,400 tons of cargo. By comparison the current giant of the skies, the Russian An-225, has an 88.4-meter wingspan and can lift 250 tons.Because the plane skims the surface during flight, it is only practical over large, smooth bodies of water. Flying close to the water, the wing’s downwash angle and tip vortices are suppressed, resulting in a greatly reduced drag which leads to outstanding cruise efficiency. This would translate into a range of 10,000 nautical miles in trans-oceanic flight. Operating from paved runways, the plane has thirty-eight fuselage-mounted landing gears with seventy-six tires to distribute the weight.
The Pelican is designed to be a hybrid GEV, allowing it to also fly at higher altitudes up to 20,000 feet. But the range would be greatly reduced to 6,500 nautical miles when not using the ground effect.While the Pelican is yet to become a prototype the concept is hardly a new one. For decades the Russians have experimented with aircraft they called WIG (Wing In Ground-effect) planes. A WIG craft, like the Pelican, sits on a cushion of air created by aerodynamics rather than by an engine.

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