The Burnelli Web Site

Popular Science

April 1995 issue

Feature Article

"MEGAPLANES - The New 800-Passenger Jetliners"

"Calculations show that an 800-passenger, double-decker BWB with a 7,000-mile flying range would be 13 percent lighter and consume 31 percent less fuel than a conventionally shaped megaplane cruising at the same 560-mph speed. On a 6,500-mile flight from Los Angeles to Sydney, Australia, for example, the savings would add up to 12,000 gallons of jet fuel." page 56

"The BWB idea is a hybrid combining elements of a pure flying wing like the Northrop B-2 stealth bomber, and traditional slender-winged airplanes. It inherits valuable traits from both parents. "The way to evaluate an airplane is to look at its weight, its surface area, and its wingspan," says BWB configuration designer Blaine Rawdon. "You want low weight for obvious reasons. Small surface area-or wetted area-means less air-friction drag, and wide wingspan gives you low vortex drag, the losses that occur due to vortices forming at the wingtips. Everything came out nicer as we converged on this shape." p. 56

"Deep-bellied and airfoil-shaped, the big bird's centerbody is a spanloader" design that generates part of the airplane's lift while providing a large interior volume for passengers, fuel and cargo. Stresses are reduced by distributing aerodynamic lift and the weight of the payload over this large area, which can be built from lighter, less expensive structures. 'When all the dust settles, you buy airplanes pretty much by the pound,' says Robert Liebeck, leader of the BWB team...." p.56

"Traditional wide-span airplanes benefit from the same effect, achieving a lift-to-drag ratio of about 18. The BWB's score on this important aerodynamic-efficiency yardstick is predicted to be at least 25-a breakthrough in airliner performance." p. 57

"Locating the duct on the back of the centerbody and burying the engines inside its trailing edge will make the BWB an unusually quiet airplane, while eliminating the risk of runway debris being inhaled by the engines. Finally, the inlet is expected reduce fuel consumption about six percent by swallowing the turbulent boundary layer of slower-moving air atop the centerbody." p.57

Letter to Editor-in-Chief from THE BURNELLI COMPANY, INC.