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.
Lockheed designed the Cheyenne using a four-blade rigid-rotor system and configured the aircraft as a compound helicopter with low-mounted wings and a tail-mounted thrusting propeller driven by a General Electric T64 turboshaft engine.
The Cheyenne was to have a high-speed dash capability to provide armed escort for the Army’s transport helicopters, such as the Bell UH-1 Iroquois.
Specifications
Crew
2
Length
54 ft 8 in (16.66 m)
Height
13 ft 8.5 in (4.178 m)
Empty weight
12,215 lb (5,541 kg)
Gross weight
18,300 lb (8,301 kg)
Max take-off weight
25,880 lb (11,739 kg)
Powerplant
1 × General Electric T64-GE-16 turboshaft engine, 3,925 shp (2,927 kW)
Main rotor diameter
51 ft 3 in (15.62 m)
Main rotor area
2,063.2 sq ft (191.68 m2)
Blade section
Root
NACA (4.6)3012 mod
Tip
NACA (0.6)3006 mod
Rotor systems
4-bladed main rotor, 4-bladed tail rotor
Propellers
3-bladed constant-speed pusher propeller
Performance
Maximum speed
212 kn (244 mph, 393 km/h)
Cruise speed
195 kn (224 mph, 361 km/h)
Range
1,063 nmi (1,223 mi, 1,969 km)
Service ceiling
20,000 ft (6,100 m)
Rate of climb
3,000 ft/min (15 m/s)
Armament
Guns
1 × nose turret with either a 40 mm (1.575 in) M129 grenade launcher or a 0.308 in (7.62×51 mm) NATO XM196 mini gun plus 1 × belly turret with an XM140 30 mm (1.181 in) cannon
