Flight test and analyses of the B-1 structural mode control system at supersonic flight conditions

Abstract

A practical structural mode control system (SMCS) that could be turned on at takeoff and be left on for the entire flight was demonstrated. The SMCS appears to be more effective in damping the key fuselage bending modes at supersonic speeds than at the design point of Mach 0.85 (for fixed gains). The SMCS has an adverse effect on high frequency symmetric modes; however, this adverse effect did not make the system unstable and does not appear to affect ride quality performance. The vertical ride quality analyses indicate that the basic configuration without active systems is satisfactory for long term exposure. If clear air turbulence were to be encountered, indications are that the SMCS would be very effective in reducing the adverse accelerations. On the other hand, lateral ride quality analyses indicate that the aircraft with the SMCS on does not quite meet the long term exposure criteria, but would be satisfactory for shot term exposure at altitude. Again, the lateral SMCS was shown to be very effective in reducing peak lateral accelerations