YAH-64
The AH-64 was first known as the Hughes YAH-64. The twin-engine, two place attack helicopter was Hughes Helicopter's (now Boeing) entry in the US Army Advanced Attack Helicopter (AAH) competition which ran from 1973 to 1976. The AAH program was initiated to develop an attack helicopter for anti-armor operations in day, night, and adverse weather conditions with emphasis on the helicopter's ability to be based with the troops in the field. The program was begun soon after the cancellation of the Lockheed AH-56 Cheyenne program. The AAH reflected a reorientation in Army thinking based on combat experience in Vietnam. Both competitors for the AAH award, the Bell YAH-63 and the Hughes YAH-64, first flew in September 1975, and two flying prototypes of each were delivered to the U.S. Army for evaluation in May 1976. The Army selected the Hughes design on 10 December 1976. Hughes was awarded a contract to begin a full-scale engineering development program that commenced in 1977.
Originally, the YAH-64 featured a T-tail design with the tail rotor mounted mid-way on the vertical stabilizer . The tail was redesigned during the Phase 2 development process into the low-set, fully movable horizontal stabilizer (stabilator) and high mounted tail rotor seen in the production aircraft. The YAH-64 Apache featured two-place crew seats arranged in tandem, as in the Huey Cobra. The Apache was equipped with a Northrop Target Acquisition and Designation Sight (TADS), with direct-view optics, passive forward-looking infrared (FLIR), low-light-level television, laser range finder with target designator, a laser tracker, integrated with a pilot's night vision sensor (PNVS), and a computerized fire control system. The system also features the Honeywell Integrated Helmet and Display Sighting System (IHADSS) which allows for quick and flexible traget acquisition by both crew menbers. The Apache features lightweight boron armor shields in the cockpit floor and sides that can withstand hits from 23mm high-explosive or armor-piercing shells. The YAH-64, was armed with the XM230E1 30mm chain gun, up to 16 Hellfire missiles, and up to 76 2.75 inch rockets.
The Apache received its production go-ahead in March 1982 with initial deliveries beginning in January 1984.
