ABSTRACT
Methodology for investigation of lateral flying and handling qualities of an airplane is
found based on stability analysis. The fighter aircraft (F4C) and the jet trainer aircraft
are used as an example models in this investigation. Effect of changing the rolling
moment due to sideslip (Lβ) and the yawing moment due to sideslip (Nβ) derivatives on
lateral-directional motion characteristics and flying qualities is evaluated for both models.
For the lateral-directional motion the MIL-F-8785C specifications were used to compare
the parameters (time to double or to half amplitude in the spiral mode (T2s), roll mode
time constant (Tr), damping ratio (ζd), and undamped natural frequency (ωnd) of the
dutch roll mode) with the minimum or maximum required limits of flying qualities.