Northrop Grumman has delivered the center fuselage for Japan's first F-35 multi-role fighter jet, designated AX-1.

The center fuselage serves as the core structure for the F-35 Joint Strike Fighter, the fifth-generation aircraft developed by a team of industrial defense organizations led by Lockheed Martin. Northrop Grumman designed and produced the center fuselage for all three F-35 variants. Japan's AX is an F-35A, which uses conventional takeoff and landing.

"This on-time delivery marks another important step in the F-35 team's drive to support and help fulfill our allies' 21st century national security requirements," Northrop Grumman Aerospace Systems F-35 program manager Brian Chappel said in a statement. "We're proud of the role that Northrop Grumman's F-35 Integrated Assembly Line is playing in increasing the affordability and availability of this fifth-generation, multirole fighter."

The center fuselage is one of 42 fuselages the company has been contracted to produce for Japan. Northrop Grumman has manufactured 206 fuselages at its Palmdale facility to date, marking the 44th delivery in 2015.

Japan has ordered a total of 42 F-35As from Lockheed Martin. The first four, including AX-1, are scheduled to undergo their final assembly and checkout at Lockheed Martin's facility in Fort Worth, Texas. The remaining 38 will be produced at Japan's new facility in Nagoya.

In addition to the center fuselage, Northrop Grumman produces the F-35's weapon system, radar, communications subsystems, and mission-planning systems and software.