U.S. Navy Vice Adm. Mat Winter assumed command of the F-35 Lightning II program on May 25, the Department of Defense announced. He replaces Air Force Lt. Gen. Christopher Bogdan as program executive officer (PEO) of the $379 billion fighter procurement.

Bogdan was appointed F-35 deputy PEO in July 2012, then became PEO in December that year. His departure from the tri-service acquisition program coincides with his retirement from the Air Force after 34 years. During a change of command ceremony at Fort Myer, Virginia, Winter commended his “bold, effective and decisive” leadership of the F-35 effort.

President Donald Trump nominated Winter to serve as PEO in March, the Pentagon announced at the time. Previously chief of naval research, he was assigned to serve as the F-35 program deputy director last August and started that job in December.

The Lockheed Martin-built F-35 is nearing the end of its system development and demonstration phase started in 2001. The schedule calls for final, Block 3F software to be delivered and flight-tested by early next year, the DOD’s F-35 Joint Program Office has said.

The Navy’s F-35C carrier variant is the last of three versions of the fifth-generation fighter to achieve combat readiness, a status the service expects to reach in 2018. The Marine Corps declared initial operational capability (IOC) of the F-35B short takeoff and vertical landing variant in July 2015; the Air Force declared IOC of the F-35A conventional variant last August.

Deliveries have started to most of the eight other nations considered F-35 partners, as well as to foreign military sales customers Israel and Japan.

“It’s been an honor to serve alongside so many great leaders and support our nation and allies,” Bogdan stated. “The F-35 weapon system is now operational and forward deployed. The size of the fleet continues to grow and we are rapidly expanding its capability. The F-35 will form the backbone of United States air combat superiority for decades to come and I know the program is in good hands as we transition leadership to Vice Adm. Winter.”