Textron’s (NYSE: TXT) Bell Helicopter subsidiary has received a potential three-year, $423 million contract modification from the U.S. Navy to produce and deliver 25 lot 14 AH-1Z aircraft in support of the U.S. Marine Corps’ H-1 upgrade program.

The company will perform work in Fort Worth and Amarillo, Texas, through February 2020 under the modification to a previously awarded fixed-price-incentive contract, the Defense Department said Wednesday.

The Naval Air Systems Command obligated the full contract amount from the service branch’s aircraft procurement funds for fiscal 2016 and 2017.

Bell AH-1Z is an attack helicopter that has a target sight platform, glass cockpits compatible with night-vision goggles, communications systems, electronic warfare self-protection tool and a forward-looking infrared system.