The F-35 program ranks among the most expensive in military procurement history. But now the F-15EX, an enhanced variant of the fourth-generation fighter, is on track to be even more expensive. 

Projections for the F-35A and the F-15EX put each plane at around $80 million. That cost is now expected to now reach $90 million for the F-15EX in Lot 2 under the contract finalized between Boeing and the Pentagon on Sept. 28. Jets in the Lot 3 contract are projected to cost $97 million apiece, and $94 million in Lot 4. ,

The new version of the 1970s vintage fighter includes a robust electronic warfare package called the Eagle Passive/Active Warning and Survivability System, or EPAWSS. 

The F-15EX differs from prior F-15 models in that it features digital flight controls, advanced cockpit touch displays, and state-of-the-art sensors. It has over three times the weapons payload capacity of the F-35.

F-15EX Fightger Costs Balloon

When the contract was signed a year ago for the first lot of aircraft, the cost stood at $80.5 million. This means that costs will increase each year until the fourth lot enters into production. 

“We're looking at ‘how do we buy at scale’. We're looking at ‘how do we partner with suppliers for long-term affordability’. We're looking at ‘how do we control our own costs in the factory, whether that's kind of infrastructure cost or whether that's efficiency that we can continue to build in?’” Mark Sears, vice president of fighters at Boeing, told Defense One. “Today's economics and inflation and workforce instability—all of that is real and so we're trying to be as proactive as possible about how do we try to overcome that or at least stem the growth in the future.” 

Ballooning costs for the non-stealthy F-15EX could prompt increased pressure to buy F-35s instead. 

Boeing hopes that foreign sales of the F-15EX will spread out the costs and make procurement cheaper. 

The F-35 and F-15EX Compared

The F-35’s radar cross-section is equivalent to an insect, while the F-15EX’s radar signature is over 40 feet across. F-35 Joint Program Office spokesperson Russ Goemaere told Defense One that the cost of each F-35A in production lots 15 through 17, delivered in 2023 through 2025, is $82.5 million per plane. 

The F-16 remains in production for foreign militaries and costs $63 million per copy. 

“We’re paying more and we're getting something that's markedly less than the value of the F-35,” Heritage Foundation Senior Research Fellow John Venable said. 

Proponents of the F-15EX contend that buying the planes will support the industrial base — Lockheed Martin and Boeing are the last two companies still building fighter jets. 

The Air Force initially planned to buy 144 F-15EXs, but the Biden administration cut that number to 80 in its 2024 budget proposal. It was partially restored to 104 by Congress in the 2024 proposal. 

Sears noted that two of the eight projected Lot 1B F-15EXs have been delivered. 

It remains to be seen whether Boeing can attract new foreign customers for the F-15EX to spread out the overall costs.

About the Author 

John Rossomando is a defense and counterterrorism analyst and served as Senior Analyst for Counterterrorism at The Investigative Project on Terrorism for eight years. His work has been featured in numerous publications such as The American Thinker, The National Interest, National Review Online, Daily Wire, Red Alert Politics, CNSNews.com, The Daily Caller, Human Events, Newsmax, The American Spectator, TownHall.com, and Crisis Magazine. He also served as senior managing editor of The Bulletin, a 100,000-circulation daily newspaper in Philadelphia, and received the Pennsylvania Associated Press Managing Editors first-place award for his reporting.