A sonic-boom mitigator mounted on the nose of a NASA F-15B worked as expected during its first airborne test, successfully flying at Mach 1.2 last Friday, Gulfstream Aerospace Corp. said this week. The Quiet Spike, which is made of composite materials, extends 24 feet from the nose of the aircraft. It creates three small shock waves that travel in parallel to each other all the way to the ground, producing less noise than typical shock waves that build up at the front of supersonic jets. Gulfstream, in collaboration with the NASA Dryden Flight Research Center, has been flight-testing the structural integrity of the retractable spike since mid-July. Friday’s supersonic flight lasted for just over an hour and reached an altitude of 45,000 feet. [more] “The fact that the Quiet Spike performed as designed at supersonic speeds and was extended and retracted without any difficulties brings us one step closer to our goal of seeing if it will reduce the sonic boom when mounted on a more appropriate platform,” said Gulfstream spokesman Pres Henne. Overland supersonic flight is now banned in the U.S., but if new technology can mitigate the effects then proposals to ease those restrictions might be forthcoming.
