Dryden Multimedia

Quiet Spike
Gulfstream Aerospace and NASA's Dryden Flight Research Center tested the structural integrity of a telescopic 'Quiet Spike' sonic boom mitigator on a NASA F-15B testbed aircraft. The Quiet Spike was developed as a means of controlling and reducing the sonic boom caused by an aircraft 'breaking' the sound barrier.

Made of advanced composite materials, the Quiet Spike weighed some 470 pounds and extended from 14 feet in subsonic flight to 24 feet in supersonic flight. Since March 2004, when Gulfstream was awarded a patent for the Quiet Spike, the device had been through extensive ground testing, including wind-tunnel testing, to arrive at the point where it was installed on an F-15B aircraft and flown. The F-15B is capable of flying at speeds in excess of Mach 2.0, or two times the speed of sound.

Once the Quiet Spike had proven to be structurally sound, it could be incorporated with confidence onto advanced low-boom configuration aircraft to further control and mitigate adverse acoustic impacts of supersonic flight. The hope was for the Quiet Spike to become an important means of changing the traditional N-wave sonic boom into smooth and more rounded pressure waves, shaped roughly like a sine wave or a sideways "S." This change in the wave shape resulted in a softer sound that is quieter than the Concorde sonic boom by a factor of 10,000.