The US Air Force's newest fighter jet just fired off a missile for the first time

• The F-15EX Eagle II recently fired an air-to-air missile over the Gulf of Mexico.
• That marked a major milestone for the jet, as it was the first time this aircraft fired a weapon.

The US Air Force's newest fighter jet, the F-15EX Eagle II, recently hit a significant milestone — it fired a weapon for the first time.

The jet, which is assigned to the 40th Flight Test Squadron, let loose an AIM-120D Advanced Medium-Range Air-to-Air Missile in pursuit of a BQM-167 target drone while flying over the Gulf of Mexico on January 25.

The missile release during the Combat Archer air-to-air weapons-system-evaluation program marked the first time a weapon was fired from this type of fighter aircraft and came after over six months of developmental and operational flight testing, the 96th Test Wing said in a statement on the shot.

It was also the first live-fire shot for the experimental test pilot Maj. Benjamin Naumann, who flew with Maj. Mark Smith. Naumann said the shot was "another important step towards fielding the aircraft to combat units."

Colton Myers, a F-15EX test project manager with the Operational Flight Program Combined Test Force, said the missile release "was an end-to-end verification of the entire weapons system, which will pave the way for more complex missile shots in the future."

The Eagle II gets its name from the F-15 Eagle and the F-15E Strike Eagle that came before it.

The F-15 Eagle is an exceptional fighter aircraft built for air dominance, but as of April, when the F-15EX Eagle II was officially rolled out and given its name, 75% of the fleet was past its service life and 10% were grounded because of structural issues, the Air Force said.

The Air Force initially ordered eight Eagle II jets and plans to eventually acquire at least 144 to replace the aging fleet of F-15C/Ds, the average age of which is over 40 years old.

The Eagle II is a two-seat aircraft, but it can be flown by a single pilot. It features fly-by-wire controls, advanced avionics, and digital cockpit displays. It also has the capacity to carry up to 30,000 pounds of air-to-air missiles and air-to-ground munitions.

Lt. Gen. Mike Loh said at the plane's unveiling ceremony in April that the new jet's capabilities would provide "significant" improvements over legacy aircraft, like an "upgrade in weapons capacity, including the ability to carry outsize weapons for these missions, and for standoff roles in the high-end fight supporting our geographic Combatant Commanders."