‘The F-15EX will be a significant component of our tactical fighter fleet with its large payload of weapons, digital network, and open architecture, in addition to our 5th-generation aircraft.’
And this quote from Air Force Colonel Sean Dorey, the F-15EX program manager, captures why a fighter legacy from the 1970s just keeps getting pulled forward into the future force plans. It’s not so much whether the Eagle can continue to fly, but whether it can continue to adapt quickly enough to justify the flight time.
The F-15EX Eagle II is a F-15 because it is one at least in silhouette and heritage. But from a design philosophy that is software-intensive and based on the concept of growth margin in computing, sensors, and weapons, it is a completely different airplane. This is important because in the real world, longevity is no longer simply a matter of fatigue life but also one’s ability to add new functionality over the next ten years without having to redesign. The EX clearly has a design philosophy that is based on a digital design philosophy and approach that is aimed at making new sensors, pods, and mission software less of a custom engineering problem and more of an ordinary problem.
Structurally, the jet is built to last. Boeing has said that the economic life of the F-15EX is 20,000 hours, and this has been proven through full-scale fatigue testing and redesign at fatigue-critical locations. In the world of fighter aircraft, where high-G, temperature, and hard landings all work to reduce the life of the airplane, a number such as this is the quiet ground upon which more public discussions of weapons and roles are built.
These are being redefined in a way that may potentially help to further extend the life of airframes. The F-15EX is increasingly being defined less as a dedicated dogfighter and more as a high-capacity carrier that can bring numbers to a fight once other options have cleared the way. The payload and number of stations on the aircraft are the telltale signs; some analyses put it this way: 23 hardpoints and 29,500 pounds of external load, making the Eagle II a flying magazine instead of a platform that has to do everything on its own.
However, the “new mission” that matters most is the standoff delivery of oversized weapons. The Air Force has specifically stated that the F-15EX is part of hypersonic integration, with Dorey saying, “In addition, it’s capable of carrying hypersonic weapons, giving it a niche role in future near-peer conflicts.” Boeing has also pointed out that the centerline station can handle weapons that are up to 22 feet long and weigh 7,000 pounds, which is a physical constraint that is quietly driving force design as much as any operational requirement. Oversized weapons require oversized planes, and the F-15’s size, which was previously required for air superiority performance, is now providing integration capabilities that smaller stealth planes simply cannot without sacrificing their key advantage.
Survivability is the hard part of a non-stealth aircraft’s ability to operate in heavily defended airspace. In this respect, the F-15EX solution is not stealth but disruption, and this is focused on the Eagle Passive/Active Warning Survivability System (EPAWSS) and, more generally, on electronic warfare. This large payload and advanced electronic warfare capability corresponds to the operational requirement of stealth aircraft to proceed to detect and engage, and the Eagle II to deliver large numbers of weapons from relatively less-exposed positions.
It is here that the “100 years” is less about a particular aircraft number and more about an idea: a foundation design that can be broken down, re-purposed, and re-engineered over the course of a century. Fighters have a shorter useful life than bombers, as the use-by date of relevance is typically shorter than the use-by date of the aircraft itself. However, the new design of the aircraft, the open architecture, and the mission set that focuses on standoff operations give the Eagle family a viable means of continuing to accumulate flight hours well beyond the time when its original mission statement should have been accomplished.
