Abstract: The approximate transfer functions of aircraft energy height to windshear field are used to study the dynamic characteristics of aircraft in the worst phugoid oscillation excitation windshear field, and then the dangerous windshear caution threshold for the windshear detecting and warning system is determined. Thus, this paper provides the criteria for the estimation of the hazard of the windshear field to aircraft flight for the design of the windshear detecting and warning system.

Key words: phugoid oscillation, air borne windshear system, dangerous windshear caution threshold