Abstract: The invention relates to remote control of an unmanned aerial vehicle, UAV, (100) from a control station (110) by means of a wireless command link (115). The UAV (100) may be controlled in an autonomous mode wherein it flies according to a primary route (R1, R1?) defined by a first set of predefined waypoints (WP1–WP8, IP). The UAV (100) may also be controlled in a manual mode wherein it flies according to an alternative primary route (R1?) defined in real-time by control commands received via the wireless command link (115). Flight control parameters are monitored in both modes, and in case a major alarm condition occurs, the UAV (100) is controlled to follow an emergency route (R2?) defined by a second set of predefined waypoints (HP1–HP7, TP1–TP9, IP). Particularly, a major alarm condition is activated if an engine failure is detected.

Abstract: A method for synthetically calculating redundant attitude and redundant heading for an aircraft using data existing in the aircraft, including angular rates p, q, r around x-, y- and z-coordinates of an aircraft-fixed (body frame) coordinate system, air data information including speed, altitude and angle of attack, includes the steps of calculating attitude and heading based on the body-frame angular rates p, q, r, estimating errors in measured body-frame magnetic field vector components, deriving a measured body-frame field magnetic field vector, estimating errors in calculated attitude and heading using the air data and the derived measured body-frame magnetic field vector components, and correcting the calculated attitude and heading using the estimated errors in attitude and heading.

Abstract: A method and an arrangement for synthetically calculating redundant attitude and redundant heading by means of existing data in an aircraft. In one embodiment the heading of the aircraft is available and in another embodiment the heading is calculated from a magnetic heading sensor. When the heading is available (redundant heading) attitude is calculated by weighting together the signals from and angular rate gyros (2) in the aircraft's flight control system, information from air data (altitude, speed, angle of attack) as well as information about heading (redundant heading). When the heading is not available, attitude and heading are calculated in one embodiment with the aid of Kalman filters (11, 22) by weighting together the signals from the angular rate gyros in the aircraft's control system, information from air data (altitude, speed, angle of attack and sideslip angle) as well as information from a magnetic heading detector existing in the aircraft.