Quiet Spike Prototype Flight Test Results

Abstract

†∗ + # Gulfstream and NASA Dryden recently completed flight testing the Quiet Spike™ installed on Dryden’s F-15B research test bed aircraft. The Quiet Spike is a segmented, telescoping nose boom that increases the aircraft overall length for sonic boom shaping. The flight test hardware is 24 ft in length when fully extended, or approximately one-third the length of the baseline F-15B. The objective of this flight test program was not to reduce the ground signature of the F-15B aircraft, but to mitigate risk associated with the design of a relatively long, articulating nose boom. Testing was performed in a flight envelope appropriate for future quiet supersonic jet aircraft (up to 1.80M). Test results indicate there are no aeroelastic instabilities of the nose boom with adequate damping present throughout the Mach number and dynamic pressure range of interest. Loads developed from flight maneuvers, turbulence, speedbrake and flap induced buffet, landing, and ground operations are well within the structural capability of the flight test hardware. In addition, the extension/retraction system performed as designed. A post-test tear-down inspection of the hardware found only superficial wear marks. The conclusion derived from the flight test program is that the Quiet Spike is a viable structural configuration for incorporation on future quiet supersonic jet aircraft.