Abstract: A virtual image display system provides video displays based upon virtual images of the external world having synchronized structural outlines superimposed on the video displays to a pilot operating an aircraft such as a helicopter in non-visual flight conditions.

Abstract: A power management symbology (PMS) display system for helicopters that provides a continually updated, combined analog/digital symbolic display of selected status information vis-a-vis the helicopter powerplant. The PMS display system includes a multi-dimensional, continuously updated, combined analog/digital display symbol that is optimized for discriminability and compatibility with respect to the pilot's visual system.

Abstract: Images are provided to a pilot in an aircraft overflying the earth by means of a helmet mounted display system. The position and attitude of the aircraft with respect to the earth and the attitude of the helmet with respect to the aircraft are monitored in order to convert a plurality of stored earth position signals into helmet coordinates. Earth points which are viewable by the pilot are displayed using symbolic images thereof such that the symbolic images coincide, from the pilot's point of view, with the actual positions of the viewable points on the earth.

Abstract: A control arrangement for use in conjunction with a flight control computer operating in response to various input signals including those received from a collective stick to control the flight regime of a helicopter, which is operative for causing the helicopter to perform bob-up and bob-down maneuvers, includes a circuitry which generates a first control signal when the helicopter is to perform a bob-up maneuver from its instantaneous altitude to a higher altitude, stores data descriptive of at least one instantaneous altitude at the time of commencement of the first control signal; issues in response to the first control signal, an ascent command signal representative of a helicopter ascent at a maximum permissible ascent rate; generates a second control signal when the helicopter is to perform a bob-down maneuver from the higher altitude to that stored in the storing means; issues, in response to the second control signal, a descent command signal representative of a helicopter descent at a maximum permis

Abstract: Pilot workload is reduced in a helicopter having a force-type, multi-axis sidearm control stick by providing a displacement-type control stick for collective blade pitch control. Either stick may be used by the pilot. When the force-type stick is employed, a trim system causes the displacement-stick to track a collective position command signal which is provided to the blade actuators. Changeover of control to the displacement-type control stick is accomplished either with a switch, or by moving the collective-type control stick. The signals associated with each control stick are alternately faded in and out to assure a smooth transition when collective control is switched over from one to the other.