The AH-64 Apache is an all-weather day-night military attack helicopter with a four-bladed main and tail rotor and a crew of two pilots who sit in tandem. The main fixed armament is a 30 mm M230 Chain Gun under the aircraft's nose. It can also carry a mixture of AGM-114 Hellfire and Hydra 70 rocket pods on four hard points mounted on its stub-wing pylons. The AH-64 is the principal attack helicopter of the United States Army, and a successor to the AH-1 Cobra.