Boeing AH-64 Apache
Role Attack helicopter
National origin United States
Manufacturer
Hughes Helicopters
McDonnell Douglas
Boeing Defense, Space & Security
First flight 30 September 1975
Introduced April 1986
Status Active, in production
Primary users
United States Army
Israel Air Force
Egyptian Air Force
Royal Netherlands Air Force
Produced 1983–present
Number built 1,174 as of February 2010
Unit cost
AH-64A: US$20 million (2007),
AH-64D (AH-64A upgrade): US$18 million (2007)
Variants AgustaWestland Apache
The Boeing AH-64 Apache is a four-blade, twin-engine attack helicopter with tailwheel-type 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. It has four hardpoints mounted on stub-wing pylons, typically carrying a mixture of AGM-114 Hellfire and Hydra 70 rocket pods. 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. AH-64 production is continued by the Boeing Defense, Space & Security division; over one thousand AH-64s have been produced to date.
The U.S. Army is the primary operator of the AH-64, however it has also become the primary attack helicopter of several nations it has been exported to, including the United Kingdom, Israel, Japan, Greece and the Netherlands. 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.
Design
The Apache has a four-blade main rotor and a four-blade tail rotor. The crew sits in tandem, with the pilot sitting behind and above the copilot/gunner. The crew compartment and fuel tanks are armored such that the aircraft will remain flyable even after sustaining hits from 23-millimeter (0.91 in) gunfire.
The AH-64 is powered by two General Electric T700 turboshaft engines with high-mounted exhausts on either side of the fuselage. Various models of engines have been used on the Apache, those in British service use engines from Rolls-Royce instead of General Electric. In 2004, General Electric Aviation began producing more powerful T700-GE-701D engines, rated at 2,000 shp (1,500 kW) for AH-64Ds.
One of the revolutionary features at the introduction of the Apache was its helmet mounted display, the Integrated Helmet and Display Sighting System (IHADSS); among other abilities the pilot or gunner can slave the helicopter's 30 mm automatic M230 Chain Gun to his helmet, making the gun track head movements to point at where he looks. The M230E1 can be alternatively fixed to a locked forward firing position, or controlled via the Target Acquisition and Designation System (TADS).
The AH-64 is designed to endure front-line environments and to operate during the day or night and in adverse weather using avionics, such as the Target Acquisition and Designation System, Pilot Night Vision System (TADS/PNVS), passive infrared countermeasures, GPS, and the IHADSS. A newer system that is replacing TADS/PNVS is Arrowhead (MTADS); it is manufactured by Lockheed Martin, a contract was made on 17 February 2005 to begin equipping all models of American Apaches.
The AH-64 is adaptable to numerous different roles within its context as Close Combat Attack (CCA), and has a customizable weapons loadout for the role desired. In addition to the 30-mm M230E1 Chain Gun, the Apache carries a range of external stores on its stub-wing pylons, typically a mixture of AGM-114 Hellfire anti-tank missiles, and Hydra 70 general-purpose unguided 70 mm (2.76 in) rockets. The Stinger and AIM-9 Sidewinder air-to-air missiles and the AGM-122 Sidearm anti-radiation missile were evaluated beginning in the late 1980s. The Stinger was initially selected over the AIM-9, but the US Army is considering the Starstreak air-to-air missile instead. The stub-wing pylons also have mounting points for use during ground helicopter maintenance; though in case of emergency the mount points can be used for harnessing personnel to the wings during transport. External fuel tanks can also be carried by the pylons to increase range and mission time.
Variants
AH-64A
The AH-64A is the original production attack helicopter. The crew sit in tandem in an armored compartment. It is powered by two GE T700 turbo-shaft engines. The A-model was equipped with the -701 engine version until 1990 when the engines were switched to the more powerful -701C version.
The Japanese Apache variant is based on the AH-64A. Japan's AH-64DJP variant can also be equipped with the AIM-92 Stinger air-to-air missiles for defense.
AH-64B
In 1991 after Operation Desert Storm, the AH-64B was a proposed upgrade to 254 AH-64As. The upgrade would have included new rotor blades, a Global Positioning System (GPS), improved navigation systems and new radios. Congress approved US$82 million to begin the Apache B upgrade. The B program was canceled in 1992. The radio, navigation, and GPS modifications, were later installed on most A-model Apaches through other upgrades.
AH-64C
Additional funding from Congress in late 1991 resulted in a program to upgrade AH-64As to an AH-64B+ version. More funding changed the plan to upgrade to AH-64C. The C upgrade would include all changes to be included in the Longbow except for mast-mounted radar and newer -700C engine versions. However, after 1993 the C designation was dropped.
The upgrades would go forward in the 1990s. With AH-64As receiving the newer engine from 1990, the only difference between the C model and the radar-equipped D model was the radar, which could be moved from one aircraft to another. It was planned to simply designate both versions AH-64D.
AH-64D
The advanced model, the AH-64D Apache Longbow, is equipped with an improved sensor suite, a glass cockpit, and weapon systems. The main improvement over the A-variant is the dome installed over the main rotor which houses the AN/APG-78 Longbow millimeter-wave Fire Control Radar (FCR) target acquisition system and the Radar Frequency Interferometer (RFI). The raised position of the radome allows for detection and launching of missiles at targets when the helicopter is hidden by an obstacle (e.g. terrain, trees or buildings). A radio modem integrated with the sensor suite allows a AH-64D to share targeting data with other D-models. This allows a group of Longbow Apaches to fire on targets detected by the FCR of a single helicopter.
The aircraft is powered by a pair of uprated T700-GE-701C engines. The forward fuselage of the aircraft was expanded to accommodate new systems for improved crashworthiness, survivability, navigation, and 'tactical internet' communications capabilities. The first of the upgraded Block II Apaches was delivered to the US Army in February 2003. Block II includes upgrades to the digital communications systems.
Block III aircraft include the following upgrades: improved digital connectivity, the joint tactical radio system, enhanced engines and drive systems, capability to control UAVs, new composite rotor blade, full IFR capability and improved landing gear. The new blades, which successfully completed flight testing in May 2004, increased the Apache's cruise speed, climb rate and payload capability. The US Army now plans to field the first Block III equipped unit in November 2012. The Army awarded a contract to begin initial production of Block III helicopters in October 2010.
In 2011 AH-64Ds will be upgraded with VNsight low-light television sensors (LLTV) that will allow ambient lighting such as street lights, beacons, headlights and laser light to be viewable in low-light conditions. Existing thermal imagers cannot currently see this kind of light.
General characteristics
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
Performance
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)
Armament
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, however, AIM-92 Stinger may also be carried.
Avionics
Lockheed Martin / Northrop Grumman AN/APG-78 Longbow fire-control radar.