H-1 upgrade program

The H-1 upgrade program is the United States Marine Corps's program to develop the AH-1Z Viper and UH-1Y Venom military helicopters to replace its aging fleets of AH-1W SuperCobras and UH-1N Twin Hueys. The contract was awarded in 1996 to Bell Helicopter, the original manufacturer of both aircraft, to design the new airframes as modernized attack and utility helicopters with considerable design commonality, to reduce operating costs.

In August 1995, the Secretary of the Navy authorized the Marine Corps to upgrade its utility and attack helicopters as a bridge until the Joint Replacement Aircraft was available in 2020. In 1996, the Marine Corps launched the H-1 upgrade program by signing a contract with Bell for upgrading 180 AH-1Ws into AH-1Zs and upgrading 100 UH-1Ns into UH-1Ys. While the original contract called for upgrading existing airframes, it was later modified in 2008 to manufacture completely new aircraft. The program also includes aircraft simulators. Richard Aboulafia, an analyst at the Teal Group, suggests that the motivation to upgrade the H-1s instead of buying new Sikorsky UH-60 Black Hawk and Boeing AH-64 Apache helicopters was to avoid risk to the Bell-Boeing V-22 Osprey program.

The AH-1Z first flew on 8 December 2000. Three prototype aircraft were delivered to NAVAIR's Naval Air Station Patuxent River in July 2002 for the flight test phase of the program. Low-rate initial production followed beginning in October 2003, with deliveries to run through 2018, however, full-rate production was delayed until 2005.

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