F-35 Program in 2025: Record Deliveries Expected but Upgrade Delays Cloud Outlook

Deliveries Set for a New High

Lockheed Martin is preparing for what could be its busiest production year yet for the F-35 Lightning II. Company officials say between 170 and 190 jets may roll off the line in 2025, a figure that would surpass previous delivery records and underline both domestic and international demand for the fifth-generation fighter.

The surge comes at a time when the F-35 fleet continues to expand across the U.S. Air Force, Navy, and Marine Corps, as well as more than a dozen allied operators. But the milestone in production masks ongoing difficulties with the aircraft’s most important modernization efforts.

TR-3: A Bottleneck Upgrade

Central to current challenges is the Technology Refresh-3 (TR-3) upgrade. This package introduces more powerful processors, enhanced memory, and an improved pilot interface—foundations needed to support the future Block 4 configuration.

Although Lockheed has stated that TR-3 development is “nearly complete,” the program has slipped behind schedule. U.S. defense officials have even withheld a portion of payments per aircraft until the upgrade is fully validated. Until TR-3 reaches operational maturity, many new F-35s are being delivered but placed in a holding pattern, awaiting retrofit before they can reach their intended combat capability.

Block 4 and Engine Improvements Facing Delays

Beyond TR-3 lies the ambitious Block 4 upgrade, which will add new weapons integration, electronic warfare improvements, and next-generation sensors. The cost of Block 4 development has now climbed above $16 billion, raising questions about budgeting and timelines.

At the same time, propulsion modernization is slipping. The Pentagon’s plan to upgrade the Pratt & Whitney F135 engine, known as the Engine Core Upgrade, is running about a year late. That delay has a knock-on effect for the aircraft’s power and cooling system, which is already stressed by the demands of future electronic systems and directed energy weapons.

New Capabilities Coming in 2025

Despite these hurdles, some tangible enhancements are on the horizon. F-35s produced from Lot 17 onward are slated to carry the new AN/APG-85 radar, an advanced electronically scanned array designed for sharper tracking and improved ground mapping.

On the training side, the Joint Simulation Environment (JSE) continues to mature. This high-fidelity digital ecosystem allows F-35 pilots to rehearse complex combat scenarios that cannot be replicated in live training—an increasingly vital tool as the aircraft evolves into a node within broader joint and coalition networks.

Cost Pressures and International Concerns

The average flyaway cost of the F-35A remains near $82 million, with the short-takeoff B model and carrier-capable C model priced higher. But with additional technology being integrated, Lockheed has warned that aircraft in Lots 18 and 19 could once again cross the $100 million threshold.

International customers have taken notice. Canada, for example, has revised its F-35 program cost upward from $19 billion to almost $28 billion, with deliveries sliding into the latter half of the decade. Meanwhile, Spain recently stepped back from plans to join the program, opting instead to consider European alternatives—decisions that illustrate how rising costs can influence strategic choices.

U.S. Procurement Outlook

The U.S. services remain the backbone of the program, yet their procurement path is shifting. The Air Force has indicated it will not return to full-rate F-35 purchases until TR-3 issues are resolved. Budget documents for fiscal 2026 already show a steep reduction in orders, cutting the Air Force buy from 48 aircraft to just 24. The Navy and Marine Corps face similar adjustments.

This cautious approach underscores the Pentagon’s desire to ensure capability maturity before committing to larger numbers, even as production lines prepare for record throughput.

Analysis: Production Success, Capability Gaps

The F-35 program in 2025 is marked by a paradox: on one hand, it is producing more aircraft than ever before, demonstrating resilience in global demand and industrial output. On the other, it continues to wrestle with the timely delivery of critical upgrades that define its long-term relevance against near-peer adversaries.

For operators, the near-term question is less about how many jets they receive, and more about whether those jets can achieve the combat capabilities envisioned. As the fighter heads toward its fourth decade of service, the program’s success will hinge on aligning production milestones with technological readiness.

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