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The AH-64 Apache is a four-blade, twin-engine attack helicopter with reverse-tricycle landing gear, 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 1 October 1975, the AH-64 features a nose-mounted sensor suite for target acquisition and night vision systems. The Apache is armed with a 30 mm M230 Chain Gun carried between the main landing gear, under the aircraft's belly. 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 was delivered to the Army in March 1997. In August 1997, Boeing and McDonnell Douglas merged to become The Boeing Company. Today, AH-64 production is continued by the Boeing Integrated Defense Systems division.
[edit] Development[edit] Advanced Attack HelicopterFollowing the cancellation of the AH-56 Cheyenne in favor of United States Air Force and Marine Corps projects like the A-10 Thunderbolt II and Harrier Jump Jet, 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 commanding fixed-wing aircraft. The Army wanted an aircraft better than the AH-1 Cobra in firepower, performance and range. It would have the maneuverability to fly nap-of-the-earth (NoE) missions.[4] To this end, the US Army issued a Request For Proposals (RFP) for an Advanced Attack Helicopter (AAH) on 15 November 1972.[5] Proposals were submitted by five manufacturers: Bell, Boeing Vertol (teamed with Grumman), Hughes, Lockheed, and Sikorsky. In 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.[6] 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.[6] 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.[7] The AH-64A then entered phase 2 of the AAH program. This called for building three preproduction AH-64s, and upgrading the two YAH-64A flight prototypes and the ground test unit up to the same standard.[8] Weapons and sensor systems were integrated and tested during this time,[6] including the new Hellfire missile.[8] [edit] Moving into productionIn 1981, three pre-production AH-64As were handed over to the US Army for Operational Test II. The Army testing was successful, but afterwards it was decided to upgrade to the T700-GE-701 version of engine, producing 1,690 shp (1,259 kW).[6] In late 1981, the AH-64 was named the "Apache" keeping with the Army's traditional use of American Indian tribal names for its helicopters. Hughes was approved for full scale production in 1982.[6] In 1983, the first production helicopter was rolled out at Hughes Helicopter's facility at Mesa, Arizona. In 1984, Hughes Helicopters was purchased by McDonnell Douglas for $470 million.[9] The helicopter unit later became part of The Boeing Company with the merger of Boeing and McDonnell Douglas in August 1997. In 1986, the incremental or flyaway cost for the AH-64A was US$7.03 million and the average unit cost was approximately US$13.9 million based on total costs.[9] In the mid-1980s, McDonnell Douglas studied an improved "AH-64B" design with an updated cockpit, new fire control system and other upgrades. In 1988 funding was approved for a multi-stage upgrade program to improve sensor and weapon avionic systems and incorporate some digital systems. However, improved technology was becoming available. It was decided to cancel the upgrade program for more ambitious changes. This would lead to the more advanced AH-64D Apache Longbow. Development of the AH-64D was approved by the Defense Acquisition Board in August 1990. The first AH-64D Apache Longbow prototype was flown on 15 April 1992.[10] On 13 October 1995 full-scale production of the Apache Longbow was approved. The first production AH-64D flew on 17 March 1997 and was delivered to the Army on 31 March 1997.[11] In 2004, General Electric Aviation began producing more powerful T700-GE-701D engines, rated at 2,000 shp (1,500 kW) for AH-64Ds.[12] The total cost of the AH-64D program is US$10.5 billion through April 2007.[13] [edit] DesignThe AH-64 is powered by two General Electric T700 turboshaft engines with high-mounted exhausts on either side of the rotor shaft. The Apache has a four-blade main rotor and four-blade tail rotor setup. The crew sits in tandem, with the pilot sitting behind and above the copilot-gunner in an armored crew compartment. The crew compartment and fuel tanks are armored such that the aircraft will remain flyable even after sustaining hits from 23 mm gunfire.[14][15] The helicopter is armed with a 30 mm automatic M230 Chain Gun that can be slaved to the gunner's Helmet mounted display, fixed to a locked forward firing position, or controlled via the Target Acquisition and Designation System (TADS). The AH-64 carries a range of external stores on its stub-wing pylons, typically a mixture of AGM-114 Hellfire anti-tank missiles, Hydra 70 general-purpose unguided 70 mm (2.75 in) rockets, and AIM-92 Stinger air-to-air missiles for countermeasures defense. In case of emergency the pylons also have mounting points for personnel transfer (mounting points are handles normally used by maintenance personnel).[16] The AH-64 is designed to endure front-line environments and to operate during the day or night and in adverse weather using avionics and electronics, such as the Target Acquisition and Designation System, Pilot Night Vision System (TADS/PNVS), passive infrared countermeasures, Global Positioning System (GPS), and the Integrated Helmet And Display Sight System (IHADSS). [edit] Operational history[edit] United States ArmyAmerican Apaches were used since 1989 in: Panama, Gulf War, Bosnia, Kosovo and in the Iraq war (Operation Iraqi Freedom). During Operation Iraqi Freedom in 2003 more than 200 American Apaches were used. The Apache was first used in combat in 1989, during Operation Just Cause, the invasion of Panama. The AH-64A Apache and the AH-64D Apache Longbow have played important roles in several Middle Eastern wars, including Operation Desert Storm in Iraq, Operation Enduring Freedom in Afghanistan, and the invasion of Iraq during Operation Iraqi Freedom in 2003. The AH-64 proved to be an excellent tank hunter, during operations, and consequently destroyed hundreds of armored vehicles (mainly of the Iraqi army). During Operation Desert Storm on 17 January 1991, eight AH-64As guided by four MH-53 Pave Low IIIs, were used to destroy a portion of the Iraqi radar network to allow bomber aircraft into Iraq without detection.[6] This was the first attack of Desert Storm.[6] The Apaches carried an asymmetrical load of Hydra 70 flechette rockets, Hellfires, and one auxiliary fuel tank each.[17] During the 100-hour ground war, a total of 277 AH-64s took part. Apaches destroyed over 500 tanks, numerous armored personnel carriers and many other vehicles during Operation Desert Storm.[6][18] Deployment of AH-64s to the Balkans took place during conflicts in Bosnia and Kosovo later in the 1990s, but the Apache encountered problems which reduced their effectiveness considerably. Criticisms included a lack of training for the crews and deficiencies in night vision equipment, fuel tanks, and aircraft survivability. An Apache crashed during training in Albania on 27 April 1999. Eventually the entire fleet in the Balkans was grounded for two weeks in December 2000. Major General Dick Cody, commanding officer of the 101st Airborne at the time, wrote a strongly worded memo to the US Army Chief of Staff about the failures in training and equipment.[19] AH-64D over Taji, Iraq 2006. During Operation Iraqi Freedom, several Apaches were damaged in combat, including one captured by Iraqi troops near Karbala on 24 March 2003, and shown on Iraqi television. The captured helicopter was destroyed via air strike one day after it was downed.[20] The 24 March attack, against an armored brigade of the Iraqi Republican Guard's Medina Division, was largely unsuccessful: US officials claimed that it was because the tank crews had set up a "flak trap" in broken terrain, employing their guns to good effect.[21][22] Iraqi officials claimed a farmer with a Brno rifle shot and brought down the Apache helicopter,[23] but the farmer denies shooting it.[24] The helicopter came down intact and neither the pilot nor co-pilot was injured in the incident, though both were captured.[21] American AH-64Ds are flying in Iraq and Afghanistan without the Longbow Fire Control Radar as there are no armored threats for coalition forces to deal with.[25] The vast majority of Apache helicopters that have taken heavy combat damage have been able to continue their assigned missions and return safely to their bases. For example, of the 33 Apaches employed in the 24 March 2003 attack, 30 were damaged by Iraqi ground fire with several being damaged beyond repair, but only one of these did not make it back to base.[22] As of 2008, eleven Apache helicopters were shot down by enemy fire during the entire war and another fifteen crashed in Iraq due to other reasons. [edit] IsraelThe Israeli Air Force (IAF) first received AH-64As in 1990.[26] The AH-64A was used to attack and destroy Hezbollah outposts in Lebanon during the 1990s, attacking in many weather conditions — day and night. During the morning of 24 May 2001, a private owned Lebanese-registered Cessna 152 flew into Israeli airspace and was intercepted by two Israeli AH-64s. One of the helicopters shot down the Cessna with an AGM-114 Hellfire missile off the coast of Netanya, killing the pilot.[27][28] During the al-Aqsa Intifada, the IAF used the AH-64 to kill senior Hamas figures, such as Ahmed Yasin and Adnan al-Ghoul, with guided missiles. In the 2006 Lebanon War, two IAF AH-64A helicopters collided, killing one pilot and wounding three, all critically. In another incident in the conflict, an IAF AH-64D crashed, killing the two crew, due to a malfunction in the main rotor.[29] [edit] United KingdomMain article: AgustaWestland Apache UK Army Air Corps Westland Apache WAH-64D Longbow displays at a UK airshow The UK operates a modified version of the Apache Longbow initially called the Westland WAH-64 Apache, and is designated Apache AH1 by the British Army. Westland has built 67 WAH-64 Apaches[30] under license from Boeing replacing the engines with more powerful Rolls-Royce units. A folding blade assembly for naval operations is another important change, allowing British Apaches to operate alongside and in support of amphibious operations, flying from Royal Navy warships and auxiliaries. The Westland Apache replaced the Westland Lynx AH7 as the British Army's tactical attack helicopter. The Apache AH1s are deployed in Afghanistan, where they are serving in support of UK and Coalition forces in the south of the country.[31] British Apaches are using the Longbow Fire Control Radar in Afghanistan, saying that it improves situational awareness and avoidance of other aircraft during tactical maneuvers.[32] [edit] The NetherlandsThe Royal Netherlands Air Force ordered 30 AH-64D Apaches in 1996,[33] after leasing 12 AH-64As. The radomes were not included, hence the Dutch AH-64Ds are not referred to as Longbows. Their first deployment was in 2001 to Djibouti, Africa. This was the first deployment of the D-model Apache.[34] They were also deployed alongside US AH-64s in support of NATO peacekeeping forces in Bosnia and Herzegovina. In 2004, six Dutch AH-64s were deployed as part of the Netherlands contribution to Multinational force in Iraq to support the Dutch ground forces. The Apaches took care of Close Combat Support and display of force. Besides they gathered information for the ground forces thanks to the highly advanced sensors and weaponsystems.[35] At the same time Dutch Apaches were also deployed to Kabul airport as part of the Netherlands contribution to ISAF. In February 2006, the Netherlands contribution to NATO forces in Afghanistan was increased from 600 to 1,400 troops and 6 AH-64s were sent in support.[36] [edit] Other and future usersJapan has ordered 50 AH-64Ds.[37] They are to be built under license by Fuji Heavy Industries, with its first helicopter delivered to the JGSDF in early 2006.[8][38] These Fuji-made AH-64Ds are to be designated "AH-64DJP".[8] In September 2003, Greece ordered 12 AH-64D in addition to existing fleet of 20 AH-64A+. Singapore purchased a total of 20 AH-64D Longbow Apache aircraft in two batches between 1999 and 2001. The United Arab Emirates purchased 30 AH-64A helicopters in 1991 and 1994, which they are now upgrading to AH-64D specification.[39] Kuwait has purchased 16 Longbow helicopters.[40] Other countries with the Apache include Egypt, and Saudi Arabia.[41] The Apache Longbow is one of several types competing for the Indian Air Force order for 22 attack helicopters. Boeing had backed out of the competition in October 2008,[42] but submitted an Apache proposal in October 2009.[43][44] [edit] Variants[edit] AH-64AThe AH-64A is the original production attack helicopter. It is powered by two GE T700 turbo-shaft engines. The crew sit in tandem in an armored compartment. The helicopter is armed with a 30 mm M230 Chain Gun that is slaved to the gunner's helmet-mounted gunsight. The AH-64A carries a range of external stores on its stub-wing pylons, including a mixture of AGM-114 Hellfire anti-tank missiles, Hydra 70 general-purpose unguided 70 mm (2.75 in) rockets, and AIM-92 Stinger air-to-air missiles for defense. [edit] AH-64BIn 1991 after Operation Desert Storm, the AH-64B was a proposed upgrade to 254 AH-64As. The upgrade included new rotor blades, a Global Positioning System (GPS), improved navigaton systems and new radios. Congress approved US$82 million to begin the Apache B upgrade. The B program was canceled in 1992.[6] The radio, navigation, and GPS modifications, would later be installed on most A-model Apaches as part of an upgrade program. [edit] AH-64CAdditional 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 engines. However, after 1993, the C designation was dropped.[6] The upgrades would go forward. However, since 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, a decision was made to not distinguish between the two versions, despite the presence or absence of the radar. [edit] AH-64D Republic of Singapore Air Force AH-64D on static display during open house The advanced model, the AH-64D Apache Longbow, is equipped with an improved sensor suite, glass cockpit, and weapon systems. The key improvement over the A-variant is the AN/APG-78 Longbow dome installed over the main rotor which houses a millimeter-wave Fire Control Radar (FCR) target acquisition system as well as the Radar Frequency Interferometer (RFI). The elevated position of the radome allows detection and (arcing) missile engagement of targets even when the helicopter itself is concealed by an obstacle (e.g. terrain, trees or buildings). Further, a radio modem integrated with the sensor suite allows a D-variant Apache to share targeting data with other AH-64Ds that do not have a line-of-sight to the target. In this manner a group of Apaches can engage multiple targets but only reveal the radome of one D-variant Apache. Apaches that include all of the improvements of the Longbow Apache, with the exception of the Fire Control Radar are still designated as "AH-64D Apache Longbows", as the radome is removable and interchangeable between aircraft. The aircraft is powered by a pair of uprated T700-GE-701C engines, and has a fully-integrated cockpit. The forward fuselage of the aircraft was expanded to accommodate new systems. In addition, the aircraft receives improved survivability, communications, and navigation capabilities. Most existing capabilities of the AH-64A Apache are retained. 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 to improve communications within the 'tactical internet'.[45] Block III improvements, slated for 2008 onwards, include increasing digitization, the joint tactical radio system, enhanced engines and drive systems, capability to control UAVs, new composite rotor blade and landing gear upgrades. The new blades, which successfully completed flight testing in May 2004, increase the Apache's cruise speed, climb rate and payload capability. The Block III System Development and Demonstration (SDD) contract was awarded to Boeing in July 2006.[45] [edit] Export ApachesA number of other models have been derived from both AH-64A and AH-64D for export. The British-built AgustaWestland Apache (assembled from kits purchased from Boeing) is based on the AH-64D with several different systems, including more powerful engines. [edit] Sea ApacheA naval version of the AH-64A was proposed for the United States Marine Corps and Navy from 1984 to 1987.[7] Multiple concepts were studied with altered landing gear arrangements, improved avionics and weapons.[46] Funding for the naval version was not provided and the Marine Corps continues to use the AH-1 SuperCobra.[7] [edit] Operators JGSDF AH-64D.
[edit] Specifications (AH-64A/D)Data from Jane's Information Group,[3] Apache AH-64[6] General characteristics
[File:AH-64 dsc04578.jpg Performance
Armament
[edit] Popular cultureMain article: Aircraft in fiction#AH-64_Apache [edit] See also
Related development Comparable aircraft
Related lists
[edit] References[edit] Notes
[edit] Bibliography
[edit] External links
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