Lockheed Martin has delivered 72 F-35 Lightning II jets to the U.S. government as of May 1, 2025, despite ongoing delays linked to the aircraft’s latest upgrade package, according to a Bloomberg News report citing the Pentagon’s F-35 Joint Program Office.
The delay centers around Technology Refresh 3 (TR-3), a critical software and hardware upgrade intended to enhance the F-35’s processing power, cockpit displays, and overall mission systems. TR-3 is a prerequisite for integrating Block 4 capabilities, which include next-generation sensors, electronic warfare improvements, and new weapons.
Initially slated for delivery in 2023, TR-3 has faced prolonged integration and testing challenges. As a result, the Pentagon has been withholding $5 million per jet from Lockheed Martin since 2024 to apply financial pressure on timely delivery and full upgrade readiness.
Despite these issues, Lockheed Martin continued to assemble and deliver aircraft configured for future TR-3 retrofitting. The 72 jets delivered are technically “flyable,” but do not yet meet the full combat-ready configuration expected with TR-3 functionality.
TR-3 Key to F-35 Modernization
TR-3 represents a foundational step in the F-35’s long-term roadmap. Without it, the aircraft cannot operate future mission software or integrate new munitions and battlefield connectivity features planned under Block 4.
Lockheed Martin and its subcontractors, including L3Harris and BAE Systems, have cited complexity in software validation and hardware-software synchronization as primary hurdles. The Pentagon’s program office is working closely with the defense contractor to resolve the delays, but a concrete timeline for TR-3-certified deliveries remains uncertain.
Pentagon’s Balancing Act
The U.S. Department of Defense faces a delicate balance: accelerating production to meet domestic and international demand while ensuring the platform’s next-generation capabilities are not compromised. The Pentagon has stated that full-rate production decisions for the F-35 remain contingent on successful TR-3 implementation.
Despite the software setback, the F-35 remains a cornerstone of U.S. and allied airpower, with over 990 aircraft delivered worldwide and multiple partner nations involved in the program.
Lockheed Martin has reiterated its commitment to delivering TR-3 capabilities across the fleet and retrofitting the already-delivered jets once the upgrade package is finalized and validated.
Javeria Sajid is an Aerospace Engineering student from NUST with a background in technology and a sharp focus on the global political landscape and defence innovation. She writes to make complex defence technologies understandable, and aspires to bridge journalism, policy, and engineering in her work.
