The Boeing Company
System for estimating airspeed of an aircraft based on a drag model

Abstract:

A system and method for estimating a plurality of airspeed parameters of an aircraft is disclosed. The system comprises one or more processors and a memory coupled to the processor. The memory storing data comprises a database and program code that, when executed by the one or more processors, causes the system to receive a plurality of operating parameters that each represent an operating condition of the aircraft. The system is further caused to determine a stability-axis drag coefficient based on the plurality of operating parameters. The stability-axis drag coefficient quantifies a stability-axis drag of the aircraft created during high speed conditions. The system is caused to determine a body-axis lift coefficient based on the plurality of operating parameters, which corresponds to a lift of the aircraft created along a vertical body-axis. The system is also caused to determine a dynamic pressure, which is used to estimate the airspeed parameters.