The AH-64 Apache is a four-blade, twin-engine attack helicopter with reverse-tricycle landing gear arrangement, and tandem cockpit for a crew of two. The Apache was developed as Model 77 by Hughes Helicopters for the United States Army's Advanced Attack Helicopter program to replace the AH-1 Cobra. First flown on 30 September 1975, the AH-64 features a nose-mounted sensor suite for target acquisition and night vision systems. The Apache is armed with a 30-millimeter (1.2 in) M230 Chain Gun carried between the main landing gear, under the aircraft's forward fuselage. The AH-64 also carries a mixture of AGM-114 Hellfire and Hydra 70 rocket pods on four hardpoints mounted on stub-wing pylons. The AH-64 also features double- and triple-redundant aircraft systems to improve survivability for the aircraft and crew in combat, as well as improved crash survivability for the pilots.
The U.S. Army selected the AH-64 over the Bell YAH-63 in 1976, awarding Hughes Helicopters a pre-production contract for two more aircraft. In 1982, the Army approved full production. McDonnell Douglas continued production and development after purchasing Hughes Helicopters from Summa Corporation in 1984. The first production AH-64D Apache Longbow, a greatly upgraded version of the original Apache, was delivered to the Army in March 1997. Presently, AH-64 production is continued by the Boeing Defense, Space & Security division; and over a thousand AH-64s have been produced so far.