Bell Helicopter has signed a $439.6 million contract to build 25 new AH-1Z Viper attack helicopters and avionics for the U.S. Marine Corps, according to a Pentagon statement. The US Navy (USN) awarded Bell a USD 440 million contract modification, known as Lot 16, as part of the US Marine Corps’ program to acquire 189 AH-1Zs.

The contract also includes the purchase of 25 store control units, which, according to Bell spokesman Michael Reilly, is the interface between the pilot and the weapon system that is used to manage the ordnance on the aircraft.

The company, which is a subsidiary of Textron Inc., will build the aircraft and store control units at its headquarters in Fort Worth and in Amarillo, Texas, the Navy announced Friday. The contract is a modification to a previously awarded fixed-price-incentive contract.

Bell Helicopter expects to finish the work by January 2022. Navy fiscal 2018 aircraft procurement funds will be obligated at the time of award, none of which will expire at the end of the current fiscal year.

The AH-1Z, known as the Zulu Cobra, is a twin-engine attack helicopter based on the Bell AH-1W SuperCobra. The upgraded avionics, weapons, and electro-optical sensors are designed to find targets at long ranges and use precision weapons to engage them at long ranges and use precision weapons to engage them at extended ranges and practice weapons.

The Zulu is the only attack helicopter in the world with a fully-integrated air-to-air missile capability.

The Bell AH-1Z’s Target Sight System provides the longest range and highest accuracy of any helicopter sight in the world. The two-seat helicopter can carry a payload of 5,764 pounds, fly as fast as 222 knots, with a range of 370 nautical miles, and up to 20,000 feet above sea level. In 2005, the Marine Corps accepted delivery of the first AH-1Z production helicopter, which was declared combat ready in 2010.