Aircraft digital virtual flight simulation method is a simulation method based on the “human-pilot-environment” mathematical model for complete flight missions. During the preliminary design phase, this method enables initial assessment of aircraft flying qualities and airworthiness compliance, effectively addressing issues that may be difficult to modify if discovered during flight test. Furthermore, this method proves effective for the airworthiness verification of different flight states or civil aircraft developments in the same flight test course, and is increasingly being adopted in civil aircraft airworthiness verification. This paper systematically introduces the aircraft digital virtual flight simulation method, with particular emphasis on flight mission digitization and digital pilot modeling. Application examples are presented in several areas: civil aircraft configuration parameter design and operating condition determination, precise flight performance calculation, civil aircraft airworthiness compliance evaluation, military aircraft flying qualities assessment, and Category Ⅲ nonlinear PIO prediction. This paper provides a practical digital computation methodology for aircraft design, airworthiness verification, and flying qualities assessment.

Blended-Wing-Body (BWB) aircraft have a relatively short fuselage and no horizontal tail, and they usually adopt podded engines and a V tail instead of a vertical tail. Generally, BWB aircraft have decreased longitudinal and directional static stability and damping. In this paper, the three-axis static and dynamic stability characteristics of an example BWB aircraft with podded engines are studied. According to the differences in flight characteristics of BWB aircraft and conventional aircraft, the different airworthiness requirements for BWB aircraft are analyzed: first, based on current airworthiness regulations and transport aircraft flying quality specification, the relaxation requirement of longitudinal static stability for BWB aircraft is studied; second, the influences of podded engines on longitudinal trim, attitude and trajectory responses and maximum directional control power requirement of BWB aircraft are analyzed; third, the changes in the proportional relationships between the takeoff characteristic speeds of the example BWB aircraft are analyzed. In view of these variations in directional control power requirement and relationships between takeoff characteristic speeds, new recommendations for airworthiness evaluation are proposed for BWB aircraft. The conclusions of this paper are helpful references for configuration design, flight control law design and airworthiness evaluation of BWB aircraft.