The Advanced Attack Helicopter (AAH) was a

United States Army The United States Army (USA) is the land warfare, land military branch, service branch of the United States Armed Forces. It is one of the eight Uniformed services of the United States, U.S. uniformed services, and is designated as the Army o ...

program to develop an advanced ground attack helicopter beginning in 1972. The Advanced Attack Helicopter program followed cancellation of the

Lockheed AH-56 Cheyenne The Lockheed AH-56 Cheyenne was an attack helicopter developed by Lockheed for the United States Army. It rose from the Army's Advanced Aerial Fire Support System (AAFSS) program to field the service's first dedicated attack helicopter. Lock ...

. After evaluating industry proposals, the AAH competition was reduced to offerings from

Bell A bell is a directly struck idiophone percussion instrument. Most bells have the shape of a hollow cup that when struck vibrates in a single strong strike tone, with its sides forming an efficient resonator. The strike may be made by an inte ...

and

Hughes Hughes may refer to: People * Hughes (surname) * Hughes (given name) Places Antarctica * Hughes Range (Antarctica), Ross Dependency * Mount Hughes, Oates Land * Hughes Basin, Oates Land * Hughes Bay, Graham Land * Hughes Bluff, Victoria La ...

. Following a flight test evaluation of prototypes, Hughes' YAH-64 was selected in December 1976.

Background

During the mid-1960s, the

initiated the Advanced Aerial Fire Support System (AAFSS) program, which led to the development of the

for use in the anti-tank gunship role. The US Army pursued the AH-1G HueyCobra as an "interim type" for the "jungle fighting" role. However, the Army's broader concern was the task of protecting Western Europe from the legions of

Warsaw Pact The Warsaw Pact (WP) or Treaty of Warsaw, formally the Treaty of Friendship, Cooperation and Mutual Assistance, was a collective defense treaty signed in Warsaw, Poland, between the Soviet Union and seven other Eastern Bloc socialist repub ...

armor to the east.First Generation Cobras
Vectorsite.net, 1 December 2008. The main scenario used by

NATO The North Atlantic Treaty Organization (NATO, ; french: Organisation du traité de l'Atlantique nord, ), also called the North Atlantic Alliance, is an intergovernmental military alliance between 30 member states – 28 European and two No ...

throughout the Cold War was that, if the

Soviet Union The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, ...

and Warsaw Pact forces were to conduct a massive tank offensive attack on Western Europe, they would probably cross either the

Fulda Gap The Fulda Gap (german: Fulda-Lücke), an area between the Hesse-Thuringian border (the former Inner German border) and Frankfurt am Main, contains two corridors of lowlands through which tanks might have driven in a surprise attack by the Sovi ...

(capturing

Frankfurt Frankfurt, officially Frankfurt am Main (; Hessian: , " Frank ford on the Main"), is the most populous city in the German state of Hesse. Its 791,000 inhabitants as of 2022 make it the fifth-most populous city in Germany. Located on it ...

first and then aiming for the westward bend of the

Rhine ), Surselva, Graubünden, Switzerland , source1_coordinates= , source1_elevation = , source2 = Rein Posteriur/Hinterrhein , source2_location = Paradies Glacier, Graubünden, Switzerland , source2_coordinates= , so ...

south of

Wiesbaden Wiesbaden () is a city in central western Germany and the capital of the state of Hesse. , it had 290,955 inhabitants, plus approximately 21,000 United States citizens (mostly associated with the United States Army). The Wiesbaden urban area ...

: a total distance of just 85 miles), or cross the

North German Plain The North German Plain or Northern Lowland (german: Norddeutsches Tiefland) is one of the major geographical regions of Germany. It is the German part of the North European Plain. The region is bounded by the coasts of the North Sea and the Balt ...

(see map). The Advanced Attack Helicopter was conceived from the need to defend against such an attack. In 1971, political friction increased between the Army and the Air Force over the close air support (CAS) mission.Campbell, Douglas. ''The Warthog and the Close Air Support Debate'', p. 84. Annapolis, MD: Naval Institute Press, 2003. . The Air Force asserted that the Cheyenne would infringe on the Air Force's CAS mission in support of the Army, which had been mandated with the

Key West Agreement The Key West Agreement is the colloquial name for the policy paper Functions of the Armed Forces and the Joint Chiefs of Staff drafted by James V. Forrestal, the first United States Secretary of Defense. Its most prominent feature was an outline f ...

of 1948.Dahl, Arden B.
The Warthog. The Best Deal the Air Force Never Wanted
', p. 2. National War College. 2003. The Department of Defense (DOD) conducted a study which concluded that the Air Force's A-X program, the Navy's proposed Harrier, and the Cheyenne were significantly different and that they did not constitute a duplication of capabilities.OAVCSA 1973, p. 9. The Army convened a special task force under General Marks in January 1972, to reevaluate the requirements for an attack helicopter. The task force conducted flight evaluations of the AH-56, along with two industry alternatives for comparison; the

Bell 309 KingCobra The Bell Model 309 KingCobra was an experimental attack helicopter developed by Bell Helicopter, based on the Bell AH-1 Cobra. Design and development Background The AH-1 Cobra was developed in the mid-1960s as an interim gunship for the U.S. A ...

and

Sikorsky S-67 Blackhawk The Sikorsky S-67 Blackhawk was a private-venture, prototype attack helicopter built in 1970 with Sikorsky Aircraft research and development (R&D) funds. A tandem, two-seat aircraft designed around the dynamic drive and rotor systems of the Sik ...

. In 1972, the Army conducted a competitive fly-off of the helicopters from the spring 1972 until July 1972. The Army determined that the three helicopters could not fulfill its requirements.Center of Military History
"Chapter V: Force Development"
''Dept. of the Army Historical Summary, 1972''. Washington, D.C.: Headquarters, Department of the Army, 1972. Accessed on 31 October 2008. In April 1972, the Senate published its report on CAS. The report recommended funding of the Air Force's A-X program, which would become the

A-10 Thunderbolt II The Fairchild Republic A-10 Thunderbolt II is a single-seat, twin-turbofan, straight-wing, subsonic attack aircraft developed by Fairchild Republic for the United States Air Force (USAF). In service since 1976, it is named for the Republic ...

, and limited procurement of the Harrier for the Navy. The report never referred to the Cheyenne by name and only offered a lukewarm recommendation for the Army to continue to seek to procure attack helicopters, so long as their survivability could be improved.Bonin, John A., MAJ, USA
''Towards the Third Dimension in Combined Arms: The Evolution of Armed Helicopters into Air Maneuver Units in Vietnam''
p. 33. Fort Leavenworth, Kansas: US Army Command and General Staff College, 22 April 1986. The Cheyenne program was canceled by the Army on 9 August 1972.Landis and Jenkins 2000, pp. 79–82. The helicopter's large size and inadequate night/all-weather capability were reasons stated by the Army for the cancellation.

Requirements, proposals, and prototypes

Following the cancellation of the AH-56 Cheyenne the US Army sought an aircraft to fill an anti-armor attack role. 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 Nap-of-the-earth (NOE) is a type of very low-altitude flight course used by military aircraft to avoid enemy detection and attack in a high-threat environment. Other, mostly older terms include "ground-hugging", "terrain masking", "flying under t ...

(NoE) missions.Bishop, Chris. ''Apache AH-64 Boeing (McDonnell Douglas) 1976–2005''. Osprey Publishing, 2005. . On 17 August 1972, the Army initiated the Advanced Attack Helicopter (AAH) program.OAVCSA 1973, p. 10. AAH sought an attack helicopter based on combat experience in Vietnam, with a lower top speed of 145 knots (269 km/h) and twin engines for improved survivability.Landis and Jenkins 2000, pp. 81–82. To this end, the US Army issued a Request For Proposals (RFP) for an Advanced Attack Helicopter (AAH) on 15 November 1972. The AAH requirements for reliability, survivability and life cycle costs were very similar to the UTTAS requirements. The Army specified that the AAH was to be powered by twin

General Electric T700 The General Electric T700 and CT7 are a family of turboshaft and turboprop engines in the class. Design and development In 1967, General Electric began work on a new turboshaft engine demonstrator designated the "GE12" in response to US Army i ...

turboshaft engines that produce 1,500 shp (1,120 kW) each. The T700 was the same powerplant fit specified for a new Army utility helicopter competition that would be won by the

UH-60 Black Hawk The Sikorsky UH-60 Black Hawk is a four-blade, twin-engine, medium-lift utility military helicopter manufactured by Sikorsky Aircraft. Sikorsky submitted the S-70 design for the United States Army's Utility Tactical Transport Aircraft System ( ...

. The AAH would be armed with a 30 millimeter cannon and 16 TOW anti-tank missiles. The missile armament specification was later modified to include an alternate load of 16 laser-guided AGM-114 Hellfire anti-tank missiles. The Hellfire was then in development and promised greater range and lethality than TOW.Model 309 KingCobra / Model 409 AAH (YAH-63)
Vectorsite.net, 1 December 2008. Proposals were submitted by five manufacturers:

, Boeing-Vertol (teamed with

Grumman The Grumman Aircraft Engineering Corporation, later Grumman Aerospace Corporation, was a 20th century American producer of military and civilian aircraft. Founded on December 6, 1929, by Leroy Grumman and his business partners, it merged in 1994 ...

Hughes Aircraft The Hughes Aircraft Company was a major American aerospace and defense contractor founded on February 14, 1934 by Howard Hughes in Glendale, California, as a division of Hughes Tool Company. The company was known for producing, among other pro ...

, Lockheed, and Sikorsky. In June 1973, Bell and Hughes Aircraft's

Toolco Aircraft Division Hughes Helicopters was a major manufacturer of military and civil helicopters from the 1950s to the 1980s. The company began in 1947, as a unit of Hughes Aircraft, then was part of the Hughes Tool Company after 1955. It became the Hughes Helic ...

(later Hughes Helicopters) were selected as finalists, and were each awarded contracts for the construction of two prototype aircraft. This began the phase 1 of the competition. Each company built two prototype helicopters for a flight test program. Bell's Model 409/YAH-63A prototype featured a three-wheel landing gear in a tricycle arrangement, and placed the pilot in the cockpit front instead of the usual rear seat, to help with nap of earth flying.Bishop, Chris. ''Huey Cobra Gunships''. Osprey Publishing, 2006. . Hughes' Model 77/YAH-64A prototype featured a three-wheel landing gear with the third gear at its tail. Its cockpit placed the pilot in the rear seat. Faced with a flight deadline of the end of September,"AAH under attack"
''Flight International'', 16 October 1975. Hughes' YAH-64 first flew on 30 September 1975, while Bell's YAH-63 first flew on 1 October. The second YAH-64's first flight was on 22 November, and second YAH-63 flew on 21 December 1975. The first YAH-63 crashed in June 1976, but a static test prototype was brought up to flight standard and, along with the second prototype, entered the flyoff against Hughes' YAH-64s. The Army put all four helicopters through a demanding program of flight testing during 1976. The Army flyoff began in June of that year.
''Flight International'', 12 June 1976. A separate competition was conducted for the sensor and targeting suite for the AAH, with Martin Marietta and Northrop submitting proposals in November 1976. During the prototype evaluation, the Army changed the AAH primary antitank weapon from the proven TOW wire-guided missile to the new Hellfire laser-guided missile, with over twice the effective range. This was risky because Hellfire had not even been flown at the time, with the initial development contract with Rockwell International signed in October 1976.
Vectorsite.net, 1 July 2007.

Selection and afterward

After evaluating test results, the Army selected Hughes' YAH-64A over Bell's YAH-63A on 10 December 1976. Both designs were regarded as good, but the Hughes design seemed to have an edge in survivability. Reasons for selecting the YAH-64A included its more damage-tolerant four-blade main rotor and reduced stability of the YAH-63's tricycle landing gear arrangement.Donald, David. ''Modern Battlefield Warplanes''. AIRtime Publishing Inc, 2004. . 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. Weapons and sensor systems were integrated and tested during this time, including the new Hellfire missile. The Phase 2 program suffered through a number of delays for various reasons and stretched out to over five years. The first Phase 2 flight, of an upgraded initial prototype, was on 28 November 1977, with the first flight of a newbuild preproduction prototype on 31 October 1979. Initial Hellfire launches had already taken place by then, with first firings in April 1979. A competitive evaluation of preproduction helicopters, one fitted with the Martin Marietta sensor / targeting suite and the other fitted with the Northrop suite, was performed, with Martin Marietta winning the competition in April 1980. An initial production order for 11 "

AH-64A Apache The Boeing AH-64 Apache () is an American twin-turboshaft attack helicopter with a tailwheel-type landing gear arrangement and a tandem cockpit for a crew of two. It features a nose-mounted sensor suite for target acquisition and night vis ...

" attack helicopters was issued on 26 March 1982.

References

Notes

Bibliography

* Donald, David. "AH-64A/D Apache and AH-64D Longbow Apache", ''Modern Battlefield Warplanes''. AIRtime Publishing Inc, 2004. . * Government Accounting Office
''Staff Study: Advanced Attack Helicopter''
Washington, D.C.: US Government Accounting Office, 1974. * Landis, Tony and Jenkins, Dennis R. ''Lockheed AH-56A Cheyenne – WarbirdTech Volume 27''. Specialty Press, 2000. . * Office of the Assistant Vice Chief of Staff of the Army (OAVCSA)
''An Abridged History of the Army Attack Helicopter Program''
Washington, DC: Department of the Army. 1973.

External links

{{commons, AH-64 Apache

Jane's AH-64 page

Military aircraft procurement programs of the United States United States military helicopters Attack helicopters