Bell AH-1Z Viper Mystery Cache

The Bell AH-1Z Viper is a twin-engine attack helicopter based on the AH-1W SuperCobra, that was developed for the United States Marine Corps (USMC). The AH-1Z features a four-blade, bearingless, composite main rotor system, uprated transmission, and a new target sighting system. The AH-1Z is part of the H-1 upgrade program. It is also called "Zulu Cobra" in reference to its variant letter.

Aspects of the AH-1Z date back to the Bell 249 in 1979, which was basically an AH-1S equipped with the four-blade main rotor system from the Bell 412. This helicopter demonstrated Bell's Cobra II design at the Farnborough Airshow in 1980. The Cobra II was to be equipped with Hellfire missiles, a new targeting system and improved engines. Later came the Cobra 2000 proposal which included General Electric T700 engines and a four-blade rotor. This design drew interest from the US Marine Corps, but funding was not available. In 1993, Bell proposed an AH-1W-based version for the UK's new attack helicopter program. The derivative design, named CobraVenom, featured a modern digital cockpit and could carry TOWs, Hellfire or Brimstone missiles. The CobraVenom design was altered in 1995 by changing to a four-blade rotor system. The design lost to the AH-64D later that year however.

General characteristics:

• Crew: 2: pilot, co-pilot/gunner (CPG)
• Capacity: 6,661 lb (3,021 kg)
• Length: 58 ft 3 in (17.8 m)
• Rotor diameter: 48 ft (14.6 m)
• Height: 14 ft 4 in (4.37 m)
• Disc area: 1,808 ft² (168.0 m²)
• Empty weight: 12,300 lb (5,580 kg)
• Useful load: 5,764 lb (2,620 kg)
• Max. takeoff weight: 18,500 lb (8,390 kg)
• Powerplant: 2 × General Electric T700-GE-401C turboshaft, 1,800 shp (1,340 kW) each
• Rotor systems: 4 blades on main rotor, 4 blades on tail rotor

Performance:

• Never exceed speed: 222 knots (255 mph, 411 km/h) in a dive
• Cruise speed: 160 kn (184 mph, 296 km/h)
• Range: 370 nmi (426 mi, 685 km)
• Combat radius: 125 nmi (144 mi, 231 km) with 2,500 lb (1,130 kg) payload
• Service ceiling: 20,000+ ft (6,000+ m)
• Rate of climb: 2,790 ft/min (14.2 m/s)