Lockheed AH-56 Cheyenne

The Army also conducted a weapons demonstration for the Senate Armed Services Committee in early 1972, to show off the Cheyenne's firepower and garner support for attack helicopter development.

The first TOW missile that was fired in the demonstration failed and went into the ground.

The second missile was fired and hit the target. Previously, 130 TOW missiles had been fired without failure, but the failure of the first missile was now linked to perception of the aircraft.

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 [Vous devez être inscrit et connecté pour voir ce lien],
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.
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The Cheyenne program was canceled by the Secretary of the Army on 9 August 1972. The helicopter's large size and inadequate night/all-weather capability were reasons stated by the Army for the cancellation.

The Cheyenne's analog and mechanical weapons systems were becoming out of date as new digital systems that were more accurate, faster, and lighter were being developed.

The Cheyenne's unit cost had increased and was likely to increase further if new avionics were incorporated.^{[Vous devez être inscrit et connecté pour voir ce lien]}

On 17 August 1972, the Army initiated the [Vous devez être inscrit et connecté pour voir ce lien] (AAH) program.^{[Vous devez être inscrit et connecté pour voir ce lien][Vous devez être inscrit et connecté pour voir ce lien]}

AAH sought an attack helicopter based on combat experience in Vietnam, with a lower top speed of 145 kn (167 mph, 269 km/h) and twin engines for improved survivability. Lockheed offered the CL-1700, a modified version of the Cheyenne with two engines and omitted the pusher propeller, without success.

The AAH program lead to the [Vous devez être inscrit et connecté pour voir ce lien], which entered service in the mid-1980s.

After the cancellation, the Army conducted an evaluation of the seventh Cheyenne equipped with the AMCS flight control system.

The testing showed the AMCS removed most of the remaining control problems, improved stability, improved handling, and decreased the pilot workload.

With the AMCS, the Cheyenne reached a speed of 215 kn (247 mph, 398 km/h) in level flight and in a dive achieved 245 knots (282 mph, 454 km/h) and demonstrated improved maneuverability at high speeds.

Prototype #7 was the last Cheyenne to fly.
Lockheed had counted on the Cheyenne to establish itself in the helicopter market with its rigid rotor technology.

But the ambitious project was unsuccessful and the firm did develop another helicopter.

Specifications (AH-56A)

Data from Jane's Aircraft

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General characteristics

• Crew: Two; one pilot, one copilot/gunner (front seat)
  
• Length: 54 ft 8 in (16.66 m)
  
• Rotor diameter: 51 ft 3 in (15.62 m)
  
• Height: 13 ft 8.5 in (4.18 m)
  
• [Vous devez être inscrit et connecté pour voir ce lien]: 12,215 lb (5,540 kg)
  
• Loaded weight: 18,300 lb (8,300 kg)
  
• [Vous devez être inscrit et connecté pour voir ce lien]: 25,880 lb (11,740 kg)
  
• Powerplant: 1× [Vous devez être inscrit et connecté pour voir ce lien] turboshaft, 3,925 shp (2,930 kW)
  
• Rotor systems: 4 blades on main rotor, 4 blades on tail rotor, 3 blades on pusher propeller
  

Armament

• Guns:
  

1 × nose turret with either an [Vous devez être inscrit et connecté pour voir ce lien] 40 mm (1.57 in) grenade launcher or an [Vous devez être inscrit et connecté pour voir ce lien] 7.62x51 mm machine gun and1 × belly turret with an [Vous devez être inscrit et connecté pour voir ce lien] 30 mm (1.18 in) cannon

• [Vous devez être inscrit et connecté pour voir ce lien]: 6
  
• Rockets: [Vous devez être inscrit et connecté pour voir ce lien]
  
• Missiles: [Vous devez être inscrit et connecté pour voir ce lien] missiles