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: 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.