Abstract: A supersonic aircraft includes an internal passageway, an articulated intake structure and an articulated exhaust structure which is connected to the intake structure by the passageway. The articulated intake structure defines an opening having a cross-section which is essentially equal to the cross-section of the aircraft's fuselage when configured for supersonic flight and smaller opening when configured for subsonic flight. Also, for supersonic flight, the cross-sectional area of the air intake structure decreases in the direction of air flow. For subsonic flight, the cross-sectional area of the air intake structure is relatively constant. For supersonic flight, the exhaust structure defines a cross-section which increases in the direction of air flow.

Abstract: Accelerations due to excitation of the natural modes of an aircraft's body are suppressed by an active suppression system. Dedicated accelerometers are positioned in the aircraft at optimal locations for sensing modal induced lateral accelerations. The accelerometer produced signals are processed through control logic which, in response thereto, and in response to aircraft velocity and altitude related signals produces output control signals. The control signals effect rudder deployment creating forces to suppress the natural mode induced accelerations.

Abstract: A computing unit (12) produces control signals which, when applied to the control inputs of a conventional numerically controlled lathe (10), cause the lathe cutting tool (60) to be positioned such that contours varying in three dimensions may be realized in a spindle (18) mounted, rotating workpiece (20). The control signals include x and z position signals, defining the position of the cutting tool with respect to the radial (24) and axial (22) axes, respectively, of the workpiece (20), and i and k lead control signals which define the distance traveled by the cutting tool, per revolution of the workpiece, in the radial (24) and axial (22) workpiece axes, respectively.A filtering process (134, 136, 140) operates to delete each control signal having i and k values which are within the x and z tolerance values, respectively, of the immediately preceding control signal, to thereby reduce both the volume of stored data and machining time.