This paper investigates the effects of the design variables of an aerial deployment mechanism on the robustness of the aerial deployment through a multibody dynamics simulation. The aircraft is modelled as three joined rigid bodies: a right wing, a left wing and a centre body. A spring-loaded hinge is adopted as an actuator for deployment. The design variables are the hinge torque and the deployment timing. The robustness is evaluated using a sigma level method. The margins for the safe deployment conditions are set for the evaluation functions. The dispersive input variables are the initial drop velocity, the surrounding gust velocity, the initial pitch angle and the initial height. The design point with a deployment torque scale value F of 0.7 and a right-wing deployment delay time TSR
of 1.0 s can safely deploy in the low-torque deployment condition. This design point is able to accomplish both a safe deployment and a lightweight deployment mechanism.