Fin flutter is the oscillation of fins caused by the aerodynamic forces. In extreme cases, the oscillation can cause destructive failure of the fins or their attachment to the airframe. The main factors affecting fin flutter are the fin material, the method of attachment and the maximum velocity that the rocket will achieve. For all high performance flights, especially minimum diameter rockets approaching or exceeding mach 1, the design must be sufficently robust to avoid failure caused by fin flutter.