Sonic Boom

CHICAGO–The Concorde is dead. Long live supersonic transport.

The Defense Advanced Research Projects Agency and the National Aviation and Aerospace Administration are testing new aircraft designs that reduce the “overpressure” that cause sonic booms, according to J. Victor LeBacqz, associate administrator of the Office of Aeronautics at NASA. If the agencies perfect a design that eliminates the boom, supersonic planes could be built that successfully carry commercial passengers across land masses, such as the United States, he said.

The idea of a supersonic transport is “not a dead duck,” LeBacqz said in an interview with Baseline magazine at the National Manufacturing Week show at McCormick Place.

DARPA and NASA last year tested a conventional aircraft and a modified aircraft in flights over the Mojave Desert last year, LeBacqz said, that reduced the shock wave that to-date has been produced by aircraft when they exceed the speed of sound.

The design that reduced the shock wave was a “fattened” fuselage. According to LeBacqz, that is a counterintuitive finding, given that the design of automobiles and other vehicles typically flattens their fronts, to reduce drag.

The experimentation of the two agencies builds on aerodynamics theory developed in the late 1960s by Cornell University professor Albert George, LeBacqz said. DARPA and NASA will now work to not just reduce the boom, but eliminate it.

That will mean not just finding the optimal design for the fuselage, but testing and refining the impact of the unexpected fuselage approach on the aircraft’s propulsion and other systems.

LeBacqz said an aircraft capable of flying over land without creating a boom is at least a decade off. But, if the boom can be eliminated, Boeing is a likely producer of aircraft that can carry passengers coast-to-coast at supersonic speeds, he indicated.

The last flight across the Atlantic of the European-built Concorde supersonic transport took place on October 24, 2003.