A detailed aerodynamic study has been carried out on separation of nose petal of a missile. Wind tunnel tests have been conducted to evaluate the force and moment coefficients of the petal at different opening angles. The requirement of pyrojack force level to open outtlie petal initially and the subsequent motion of the petal has been studied. Trajectories of the petal after releasing from the Hinge at different release angles are computed and an optimum angle at which the petal is to be disengaged from the Hinge is chosen so as to have clean separation without interfering with the missile. © 1996 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.