Bird impact on an aeroengine rotating stage may cause the blades split and hit the engine casing subsequently.This phenomenon was studied here by using MSC software.The result shows the entire blade loss involving large mass provides a high possibility of punching through the casing.This rushing blade may collide with other blades and trigger new blade loss and containment problems(secondary damage).Partially broken blade loss could also exist

but this kind of accident is less critical at most of time

which usually can not break the casing nor trigger any secondary damage.The wide coexistence of swift movements

large deformations

unrecoverable breakages and energy exchange processes will make this process much more complicated.