The F-35 Lightning II celebrated a historic milestone as the worldwide fleet has officially reached one million flight hours logged by 16 services with more than 1,100 aircraft.
The F-35 Lightning II Joint Program Office announced on Mar. 3, 2025, a historic milestone for the for the 5th generation fighter, as the F-35 fleet has officially reached one million hours of logged flight time. This impressive result is based on the cumulative flight hours from all 16 services that are currently operating the F-35, encompassing test and operational missions, including training sorties and real-world combat.
This incredible number of hours not only highlights the reliability of the F-35 platform, but also underscores the massive work “behind the scenes” required to maintain a constant operational readiness. Thousands of people are employed in logistics and support roles to ensure the F-35 is ready to take to the skies around the clock.
As Lt. Gen Michael Schmidt, Program Executive Officer for the F-35 Lightning II Joint Program Office stated, “This milestone is not just a testament to the F-35’s unmatched capability, but also the resilience and commitment of everyone involved in the program.”
Milestone Alert! 🏆
The F-35 Lightning II has officially logged one million flight hours!
This impressive milestone spans both testing and operational missions across all 16 services currently flying the F-35.
It also underscores the aircraft’s proven performance, remarkable… pic.twitter.com/CJ3wjBs26n
— F-35 Lightning II Joint Program Office (@theF35JPO) March 3, 2025
A quick look at the F-35 Program
In 1997, Lockheed Martin and Boeing were selected to develop prototypes for the concept demonstration phase of the Joint Strike Fighter (JSF) Program, an initiative aimed at creating a versatile multirole fighter aircraft able to serve the needs of different armed forces. Lockheed Martin and Boeing presented the X-35 and the X-32 prototypes, respectively.
After a series of flight demonstrations and tactical considerations, the X-35 platform was considered a better choice to meet the diverse needs of the program aimed to develop three variants with different capabilities, including a Short Take Off and Vertical Landing (STOVL) option for the so called “B” model.
On Oct. 26, 2001, Lockheed Martin, teamed with Northrop Grumman and BAE Systems, was awarded as the selected winner of the Joint Strike Fighter System Design and Development Contract. During this crucial phase, the X-35 was vastly improved until reaching the capabilities of the first production prototype of the CTOL variant (Conventional Take Off and Landing) on Feb. 20, 2006. Starting from that day, the newly renamed F-35 aircraft outscores all the planned goals until reaching the operational squadrons and further proving as we know today its unmatched capabilities.
Today, the F-35 is the choice of 20 countries, and the Lightning II fleet is stationed across 48 bases worldwide, with 36 of these located ashore and 12 aboard naval assets. By February 2025, more than 1,110 aircraft had been delivered to the customers around the globe. Currently, 16 services operate the jet, and 13 reached the Initial Operational Capability (IOC),
As the F-35 fleet continues to expand, so does its support network too. The F-35 community, which includes not just pilots but also a vast number of personnel involved in the maintenance process, is constantly growing, over 2,790 pilots are now rated on the F-35, in addition a total of over 17,690 trained maintainers are supporting the fleet.
Considering that the F-35 has accumulated over one million flight hours across its global fleet, its accident rate remains relatively low, even in light of some recent crashes. To date, there have been approximately 16 crashes, resulting in an accident rate of about 1.6 per 100,000 flight hours. This rate, when examined over the aircraft’s lifetime, is significantly lower than that of older platforms like the F-16 and F-15.
From flight hours to engine enhancements, the ongoing F-35 journey
As a direct consequence of flying the F-35 fleet past the one million hours barrier, the F-135 engine that powers the F-35 fleet inevitably passed the same goal. To date, Pratt & Whitney has delivered more than 1,300 F-135 production engines to the Lightning II customers.
As Jill Albertelli, President of Military Engines at Pratt & Whitney, stated in a recent press release, “The F-135 engine plays a critical role in maintaining global air superiority for the U.S. and its allies, as it enables the F-35 mission in even the most contested environments. The engine has powered every F-35 since the fighter’s first flight in 2006, providing exceptional safety and readiness rates”.
The heart of the F-35 delivers a generational leap in performance and reliability, gaining customers’ trust. It continuously exceeds full mission capability rate requirements of 94%, offering operators an exceptional and unmatched safety record.
The F-35 is constantly upgraded to better match the combat field requirements, and the engine, as a vital part of the combat platform, is receiving a further upgrade to allow unmatchable tactical performances. Pratt & Whitney is actively working on the Engine Core Upgrade (ECU), a significant upgrade to meet the growing demands requested by the integration of new weapons and systems with the Block 4 upgrade.
The ECU will provide enhanced electrical power and improved cooling capabilities to support the advanced weapons systems and cutting-edge technologies introduced by the Block 4. Designed as a tri-variant upgrade, the ECU can be retrofitted to both already fielded F-35s and new production models, allowing a seamless integration across all models. This common solution reduces logistical demands while helping to maintain high operational standards and performance throughout the fleet.
