Catastrophic yaw. Why, what, how?

Abstract

Flight dynamics problems in tail stabilized missiles and bombs appear when failing to achieve their design steady-state motion because the rolling velocity occasionally locks to the pitch frequency giving rise to wobbling motions that can reach the quality of catastrophic. The flight condition attained when the coincidence between the roll and the pitch frequency persists is called roll lock-in and the large amplitude oscillation regime, catastrophic yaw. This event can occur at subsonic and supersonic velocities and invariably leads to catastrophic failure of the flight. The purpose of this paper is to give a visual explanation of the mechanism conducive to roll lock-in and catastrophic yaw and relieving means by answering the three questions: Why does the wobbling motion appear?, What is it that makes the wobbling grow to very large amplitudes? and How can catastrophic yaw be prevented?