The 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.[13][14]
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).[15]
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).
Tuesday, November 17, 2009
Development
[edit] Advanced Attack Helicopter
Following 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.[3] To this end, the US Army issued a Request For Proposals (RFP) for an Advanced Attack Helicopter (AAH) on 15 November 1972.[4]
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.[5]
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.[5] 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.[6]
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.[7] Weapons and sensor systems were integrated and tested during this time,[5] including the new Hellfire missile.[7]
[edit] Moving into production
A YAH-64 in 1984
In 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).[5] 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.[5] 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.[8] 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.[8]
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.[9] 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.[10]
In 2004, General Electric Aviation began producing more powerful T700-GE-701D engines, rated at 2,000 shp (1,500 kW) for AH-64Ds.[11] The total cost of the AH-64D program is US$10.5 billion through April 2007.[12]
Following 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.[3] To this end, the US Army issued a Request For Proposals (RFP) for an Advanced Attack Helicopter (AAH) on 15 November 1972.[4]
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.[5]
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.[5] 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.[6]
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.[7] Weapons and sensor systems were integrated and tested during this time,[5] including the new Hellfire missile.[7]
[edit] Moving into production
A YAH-64 in 1984
In 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).[5] 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.[5] 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.[8] 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.[8]
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.[9] 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.[10]
In 2004, General Electric Aviation began producing more powerful T700-GE-701D engines, rated at 2,000 shp (1,500 kW) for AH-64Ds.[11] The total cost of the AH-64D program is US$10.5 billion through April 2007.[12]
AH-64 Apache
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.
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.
Subscribe to:
Posts (Atom)