The U.S. Air Force announced that they officially accepted the first of 144 new F-15EX fighter jets from Boeing.

An F-15EX Program Manager explained what the new fighter jet’s rollout means for the Air Force, saying “this is a big moment for the Air Force,” and explaining how although the F-15EX is a 4th generation fighter, it will work closely with more advanced jets in the future. “With its large weapons capacity, digital backbone, and open architecture, the F-15EX will be a key element of our tactical fighter fleet and complement 5th-generation assets. In addition, it’s capable of carrying hypersonic weapons, giving it a niche role in future near-peer conflicts.”

Why F-15EX Matters 

As per the National Defense Strategy, the Air Force is obligated to buy 72 new fighter jets per year in order to maintain fleet levels. The F-15C/D fleet’s average age is 37 years, meaning that many of these airframes will soon reach the end of their service lives. And the F-15EX is an easy replacement solution.

Thanks to the aircraft’s similarity to the older F-15C/Ds it replaces, pilots can more easily transition to the new EX from their legacy aircraft with minimal pilot training. Admittedly cost-effectiveness was also a factor in choosing the F-15EX to replace legacy airframes. The F-22 Raptors (a much more advanced stealth fighter) production equipment was retired in the late 2000s, leaving the advanced but expensive F-35 as the only other 5th generation alternative. On the other hand, Boeing continues to build and export F-15s, therefore providing a lower-cost solution.

But Not Stealth...

The Air Force acknowledges that the F-15 — even the advanced EX variant — would struggle to survive in airspace against a near-peer rival armed with modern air defenses. It could however serve as a heavy-duty gun truck for 5th generation stealth jets like the F-22 and F-35.

One of the drawbacks to stealth fighters are their weapon carrying capacity. In order to maintain their stealth profile, they’re forced to carry weapons internally, where they are unable to be picked up by enemy radar. Though this preserves their stealthy characteristics, it limits the total amount of munitions they’re able to fly into battle with.

F-15EX Is a Real Bomb Truck

As an explicitly non-stealthy platform, the F-15EX is free to carry as many weapons as it would like to: with an 30,000-pound ordnance capacity, they easily outclass the F-35’s smaller 15,000-18,000 pound weapons payload, depending on the variant. If equipped with the United States new hypersonic missiles, the F-15EX could receive targeting data from stealthy spotter planes and launch missiles at targets from a safe distance.

So despite the F-15 family’s advanced age — the first F-15 airframe was first introduced into service in the mid-1970s — it could remain relevant and combat-effective well into the 21st century.

Caleb Larson is a defense writer based in Europe. He holds a Master of Public Policy and covers U.S. and Russian security, European defense issues, and German politics and culture.