The Boeing AH-64 Apache is a four-blade, twin-engine attack helicopter with a tailwheel-type landing gear arrangement, and a tandem cockpit for a two-man crew. 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. It has four hardpoints mounted on stub-wing pylons, typically carrying a mixture of AGM-114 Hellfire missiles and Hydra 70 rocket pods. The AH-64 features multiple aircraft systems with built-in redundancy to improve survivability in combat; improved crash survivability for the crew has also been prioritized.
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, an upgraded version of the original Apache, was delivered to the Army in March 1997. Production has been continued by Boeing Defense, Space & Security; over one thousand AH-64s have been produced to date.
The U.S. Army is the primary operator of the AH-64; it has also become the primary attack helicopter of multiple nations, including Greece, Japan, Israel, the Netherlands and Singapore; as well as being produced under license in the United Kingdom as the AgustaWestland Apache. U.S. AH-64s have served in conflicts in Panama, Persian Gulf War, Kosovo War, Afghanistan, and Iraq. Israel has made active use of the Apache in its military conflicts in Lebanon and Gaza Strip, while two coalition allies have deployed their AH-64s in Afghanistan and Iraq.
Following the cancellation of the AH-56 Cheyenne in 1972, in favor of United States Air Force and Marine Corps projects like the A-10 Thunderbolt II and Harrier, the United States Army sought an aircraft to fill an anti-armor attack role that would still be under Army command; the 1948 Key West Agreement forbade the Army from owning fixed-wing aircraft. The Army wanted an aircraft better than the AH-1 Cobra in firepower, performance and range. It would have the maneuverability for terrain following nap-of-the-earth (NoE) flying. To this end, the US Army issued a Request For Proposals (RFP) for an Advanced Attack Helicopter (AAH) on 15 November 1972. As a sign of the importance of this project, in September 1973 the Army designated their five most important projects, the "Big Five" with AAH included.
Proposals were submitted by Bell, Boeing Vertol/Grumman team, Hughes, Lockheed, and Sikorsky. In July 1973, the U.S. Department of Defense selected finalists Bell and Hughes Aircraft's Toolco Aircraft Division (later Hughes Helicopters). This began the phase 1 of the competition. Each company built prototype helicopters and went through a flight test program. Hughes' Model 77/YAH-64A prototype first flew on 30 September 1975, while Bell's Model 409/YAH-63A prototype first flew on 1 October. After evaluating test results, the Army selected Hughes' YAH-64A over Bell's YAH-63A in 1976. Reasons for selecting the YAH-64A included its more damage tolerant four-blade main rotor and the instability of the YAH-63's tricycle landing gear arrangement.
The AH-64A then entered phase 2 of the AAH program. This called for building three pre-production AH-64s, and upgrading the two YAH-64A flight prototypes and the ground test unit up to the same standard. Weapons and sensor systems were integrated and tested during this time, including the new AGM-114 Hellfire missile. The Hellfire had been developed in the 1970s as a helicopter-launched fire-and-forget weapon.
Crew: 2 (pilot, and co-pilot/gunner)
Length: 58.17 ft (17.73 m) (with both rotors turning)
Rotor diameter: 48 ft 0 in (14.63 m)
Height: 12.7 ft (3.87 m)
Disc area: 1,809.5 ft² (168.11 m²)
Empty weight: 11,387 lb (5,165 kg)
Loaded weight: 17,650 lb (8,000 kg)
Max takeoff weight: 23,000 lb (10,433 kg)
Powerplant: 2 × General Electric T700-GE-701 and later upgraded to T700-GE-701C (1990–present) & T700-GE-701D (AH-64D block III) turboshafts, -701: 1,690 shp, -701C: 1,890 shp, -701D: 2,000 shp (-701: 1,260 kW, -701C: 1,490 kW, -701D: 1,490 kW) each
Fuselage length: 49 ft 5 in (15.06 m)
Rotor systems: 4 blade main rotor, 4 blade tail rotor in non-orthogonal alignment
Never exceed speed: 197 knots (227 mph, 365 km/h)
Maximum speed: 158 knots (182 mph, 293 km/h)
Cruise speed: 143 knots (165 mph, 265 km/h)
Range: 257 nmi (295 mi, 476 km) with Longbow radar mast
Combat radius: 260 nmi (300 mi, 480 km)
Ferry range: 1,024 nmi (1,180 mi, 1,900 km)
Service ceiling: 21,000 ft (6,400 m) minimum loaded
Rate of climb: 2,500 ft/min (12.7 m/s)
Disc loading: 9.80 lb/ft² (47.9 kg/m²)
Power/mass: 0.18 hp/lb (0.31 kW/kg)
Guns: 1× 30 × 113 mm (1.18 × 4.45 in) M230 Chain Gun with 1,200 rounds
Hardpoints: Four pylon stations on the stub wings. Longbows also have a station on each wingtip for an AIM-92 ATAS twin missile pack.
Rockets: Hydra 70 air-to-ground rockets
Missiles: Typically AGM-114 Hellfire variants; AIM-92 Stinger may also be carried.
Other model helicopters:Ka-58, RAH-66 Comanche, UH-60 Black Hawk, AH-64 Apache, Ka-52 Alligator, PAH-2 Eurocopter, Ka-50 Black Shark, AH-1W Super Cobra, Mi-24 Hint, Mi-8 Hip, AS-332 Super Puma, UH-1 Iroqoies, MD-500