Real-time Estimation of AOS based on Constant Wind Field Assumption

Generally, the angle of sideslip (AOS) of the aircraft is measured by the AOS sensor during the flight test. A real-time AOS estimation method which uses the parameters from the GPS, inertial system, the angle of attack vane and air data system is presented in this paper. The method mainly uses the coordinate transformation to get the true airspeed vector in the body axis system with a constant wind field assumption, and then to calculate the AOS according to the true airspeed from the air data system. In order to get the wind field information, a zero AOS segment should be added to the flight procedure. The method can be applied in on-board or telemetry flight test monitoring system to replace the AOS sensor, and provide real-time AOS for the flight crew and ground analyst.