The Mcdonnell Douglas F-15 Eagle and its subsequent variants have served as America’s workhorse intercept fighters for over 40 years. For a short time, it seemed as though the F-15 would fade into history as it was being replaced by its stealthy successor, the F-22 Raptor. But the F-22 program ended and its supply chain was cannibalized to support F-35 production.

America’s relatively small fleet of fifth-generation air superiority fighters isn’t large enough to replace the venerable F-15. Instead, Uncle Sam has agreed to purchase more fourth-generation F-15s to replace those quickly aging out of service.

So what is it about the F-15 that’s so special that America’s Air Force can’t seem to get enough of them? Quite a bit, actually.

1) It’s the Fastest Fighter Jet in America’s Arsenal

Although the F-35 Joint Strike Fighter tends to garner most of the headlines, the F-15Cs and F-15Ds currently run by the U.S. Air Force actually beat out the F-35 in a handful of crucial air-combat metrics. The F-35, it’s important to note, wasn’t designed to serve as a dedicated dogfighter: it was built to engage ground targets primarily. The  F-15, on the other hand, was designed from the ground up to go toe to toe with the best Soviet fighters in the sky — and back then Russian fighters were really something to be feared.

The F-15’s top speed, of slightly over Mach 2.4 or 1,875 miles per hour, is the subject of a bit of debate, as many claim the powerful fighter can go even faster. Either way, it leaves platforms like the F-35 — with a top speed of just 1,230 miles per hour or so — in its dust. Even the top-of-the-line F-22 can only achieve Mach 2.2. This gives the F-15 the crown of America’s fastest fighter jet.

2) It’s Got Serious Range

While the U.S. Navy struggles to find ways to increase the operational range of its carrier-based F/A-18 Super Hornets and F-35C Joint Strike Fighters to stretch carrier ops further away from Chinese anti-ship ship missiles, the Air Force’s F-15s are boasting around three times the range of their Navy peers when flying with their three external fuel tanks. In total, the F-15 can cover around 3,000 nautical miles without needing to refuel. Thanks to its inflight refueling capabilities, it could feasibly even stay airborne and in the fight for as long as the pilot, and its ordnance, last.

3) It’s Got a Perfect Combat Record

Despite being in operation for over four decades and serving in the air forces of not just the United States, but also Japan, Israel, South Korea, Saudi Arabia, Singapore, and Qatar, no F-15 has ever been shot down by an opposing force. Unlike the F-35 and F-22, which rely on stealth to avoid detection and therefore, engagement, the F-15 has never been sneaky. Without stealth to protect the aircraft from opposing fighters or ground-based air defenses, F-15 pilots have had to rely on tactics, skill, and speed to outmaneuver or entirely avoid enemy contact.

This article was originally published in January 2020. It has been edited for republication.