The Vietnam War was the first conflict in which helicopters were used in large numbers. However, the helicopters used were, besides the Bell AH-1G "Cobra", only transport and reconnaissance helicopters, which were not developed for combat and only lightly armed. The United States lost over 5,000 helicopters and that in a war in that the enemy was as large as in a conventional battle in World War II, for example. Not only that, because of the tropical climate and the high temperature and humidity, the highly stressed components corroded much faster.
Already in 1964 the US Army contracted an heavy attack helicopter. The result of the program was the Lockheed AH-56 Cheyenne, an attack helicopter designed to attack targets performing a nosedive with high speeds. But this tactic showed later to be problematic, because testing showed that the helicopter is, while performing the nosedive, an easy target for enemies. And because of the fact that the whole Cheyenne helicopter was only designed to attack with nosedives, making it too dangerous for combat, the project AH-56 was cancelled.The US Army searched for the second attempt a helicopter with better maneuverability, the ability to perform night missions and outstanding low-level flight performance. The new helicopter should be used in the forested, hilly and mountainous area, like in Europe and Asia. All this criteria was fulfilled perfectly by the YAH-64 prototype, during its test flights, beginning on 30th September 1975, so that the helicopter was able to enter production after thoroughly testing in March 1982; the unit cost was about 17 million US dollars. On 26th January 1984 the first AH-64 entered service with the US Army. Until July 1993 800, until October 1995 900 and until the year 2000 1048 AH-64 Apache were built in many different variants.
AH-64D Apache LongbowEdit
An improved version of the AH-64, the first of six AH-64D prototypes[N 1] made it's initial flight - without longbow radar - on 15 April 1992. This was followed by the initial flights of the second (13 November 1992), third (30 June 1993), forth (4 October 1993), fifth (19 January 1994) and sixth (4 March 1994) prototypes.
- AH-64A: Baseline model with T700-GE-701 engines. Surviving examples in US service upgraded to AH-64D standard. New or ex US Army examples delivered to Egypt (36), Greece (20), Israel (42 - half ex US Army), Saudi Arabia (12) and United Arab Emirates (30).
- AH-64C: Initial designation for fifth and sixth AH-64D prototypes, intended to identify AH-64s upgraded with AH-64D features except Longbow Radar and uprated engines.
- AH-64D: Current version with T700-GE-701C engines.
- WAH-64: Designation for 67 AH-64Ds with RTM322 engines, built by Westland for British Army Air Corps.
|AH-64A Apache||AH-64D Apache Longbow|
|Type||Attack helicopter||Attack helicopter|
|Length||17.76 m||17.76 m|
|Fuselage length||14.97 m||14.97 m|
|Rotor diameter||14.63 m||14.63 m|
|Height||4.30 m||4.95 m|
|Disc area||168.11 m²||168.11m²|
|Empty weight||5,165 kg||5,352 kg|
|Loaded weight||6,552 kg||7,480 kg|
|Max. takeoff weight||9,525 kg||10,423 kg|
|Powerplant||2 General Electric T700-GE-701 engines with 1,696 horsepower||two General Electric T700-GE-701C engines with 1,940 horsepower|
|Maximum speed||293 km/h||293 km/h|
|Range||482 km||407 km|
|Service ceiling||6,400 m||5,915 m|
|Rate of climb||12.7 m/s||7.5 m/s|
- ↑ The last two were initially designated AH-64C when delivered in early 1994, before the AH-64C designation was cancelled.