A report in the British newspaper the Daily Mail says Boeing, Gulfstream and Lockheed Martin will unveil concepts for supersonic business jets capable of 2,500 mph and a London-to-Sydney flight time of four hours at the Farnborough Air Show next month. The newspaper quotes unnamed sources as saying the aerospace heavyweights have partnered with NASA to come up with designs that muffle the sonic boom, a key consideration in the marketability of such aircraft. An unnamed Gulfstream engineer is quoted as saying the result is "closer to a puff or a plop."
Gulfstream has been working on its X-54 quiet supersonic concept aircraft for four years and has kept it under wraps. It's believed to be an evolution of experiments conducted with NASA starting in 2005 to reduce the sonic boom to an acceptable level. The curtain may be pulled back a little on it at Farnborough. Both Boeing and Lockheed Martin have experience in supersonic designs but not in business jet-type aircraft. There are other hopefuls in the supersonic bizjet race but none have built an actual airplane yet.