U.S. Air Force named the F-15EX fighter jet ‘Eagle II’ during a naming ceremony at Eglin Air Force Base, April. 7.

During the ceremony, the Air Force’s newest fighter aircraft has officially been named Eagle II.

The official designation of F-15EX fighter aircraft announced Lt. Gen. Duke Z. Richardson, the Military Deputy, Office of the Assistant Secretary of the Air Force for Acquisition, Technology.

He also added that 10 percent of the current F-15C/D fleet is grounded due to structural issues, while 75 percent of the jets have exceeded their planned service life. With a 20,000-hour planned airframe lifespan, the F-15EX is likely to be around for at least half a century.

According to the Air Force Magazine, the Air National Guard will be the first to receive the new jet operationally. ANG Director Lt. Gen. Michael A. Loh said during the ceremony the F-15EX’s improvements will be key to its mission of homeland defense.

“The Air National Guard flies 93 percent of homeland defense missions, and along with the F-35A, the F-15EX will help ensure that legacy for many decades to come,” he said. “These brand-new aircraft represent a significant upgrade over the legacy F-15C. A significant upgrade in weapons capacity, including the ability to carry outsize weapons, for these missions and for stand-off roles in the high-end fight.”

The totality of the Air National Guard’s F-15C/D fleet will be replaced by either F-15EXs or F-35As, said Lt. Gen. Mike Loh, Air National Guard director.

The latest iteration of the F-15 Eagle, the F-15EX features an increased payload capacity, fly-by-wire controls, a digital cockpit, modernized sensors, radars, and electronic warfare capabilities.

The Defense News said that in total, the service plans to buy at least 144 F-15EXs to replace the F-15C/D fleet, which has an average age of 37 years and is starting to endure structural strain.