The Block 4 version of the F-35 strike fighter—the omnibus upgrade program after the Block 3F configuration is deployed with all three services—will be “sorted out in the next few months,” Pentagon acquisition chief Frank Kendall said Friday. There will be upgrades “in two-year increments,” roughly alternating hardware and software improvements, and the length of each one “drives the length of time” it will take to field it, he added. Block 4 improvements will be deployed between 2019 and 2025, Kendall said; presumably a Block 5 will follow after that. Block 4 will also include integration of foreign weapons desired by partner nations, such as Norway, Turkey, and the UK, he said. Navy acquisition chief Sean Stackley, also on the telecon, said the Pentagon is breaking the upgrade into smaller increments to avoid “one big bang” of new capabilities all at once, hoping to smooth the path of improvements. Air Force acquisition chief William LaPLante said the timing of the increments is roughly based on Moore’s Law, which predicts a doubling of electronic capability every two years or so, and is considered a “best practice” borrowed from industry. Kendall said, “I would expect the F-35 will be upgraded continuously” over its lifespan. The jet is spec’d for 8,000 hours, but the program is testing the structure to three lifetimes, program manager Lt. Gen. Christopher Bogdan noted.
Air Force Inks Deal for 22 More Boeing F-15EX Fighters
Sept. 29, 2026
The Air Force awarded Boeing a $2.38 billion contract for 22 F-15EX Eagle II fighters on Sept. 29, narrowly meeting a deadline to use funds from last summer’s reconciliation bill or face cuts.