F-35 Block 4 Upgrade Delayed Until 2031

-

The modernization of the F-35 Block 4 program has encountered significant delays, with the U.S. Department of Defense now projecting its completion no earlier than 2031. This marks a five-year setback from the original timeline, raising concerns about the program’s long-term viability and strategic implications. The delay reflects broader challenges in defense procurement and technological integration within complex weapons systems.

F-35. Photo: af.mil

In response to these challenges, the Block 4 program has undergone a major restructuring, resulting in the creation of several subprograms. These subprograms will feature a reduced number of capabilities compared to the initial plan, which originally included 66 distinct upgrades. The final acquisition planning document, expected in fall 2025, will determine which of these capabilities will be retained moving forward.

The delay is further compounded by the dependency of certain advanced features on the upgraded F135 engine, which itself is facing production delays. The F135 engine upgrade is now projected to enter production no earlier than 2031, pushing back the deployment of post-Block 4 capabilities. Originally scheduled for 2029, these features are now unlikely to be operational before 2033, creating a ripple effect across the program’s development timeline.

Financial oversight has also come under scrutiny, particularly regarding the cost-effectiveness of the Block 4 upgrade. The last official cost estimate in 2021 placed the program at $16.5 billion, but a revised figure is expected by the end of 2025. The Government Accountability Office (GAO) has criticized the use of contract incentives that reward contractors despite delays in aircraft and engine deliveries.

Production performance has been inconsistent, with Lockheed Martin and Pratt & Whitney both experiencing setbacks throughout 2024. These delays are largely attributed to supply chain disruptions and technological hurdles that have hindered the timely delivery of F-35 aircraft and F135 engines. The cascading impact of these issues has affected not only the Block 4 timeline but also broader operational readiness across the fleet.

Popular News

Next-Generation SmarTrack Blue Force Tracking for Soldiers in GNSS (GPS)-Denied Environments

-
Image
In modern military and emergency response operations, reliable communication and precise location tracking are critical for mission success. SmarTrack, developed by Elbit Systems, represents a breakthrough in Blue Force Tracking technology, offering unmatched capabilities for soldiers, special forces, mechanized infantry, and first responders. Unlike traditional systems that rely heavily on GNSS (GPS), SmarTrack ensures continuous performance even in GNSS-denied environments, making it a game-changer for complex and high-risk missions. Photo: Elbit Systems Reliable Location Tracking Without GNSS One of the most significant advantages of SmarTrack is its ability to deliver accurate positioning without depending on satellite signals. In urban warfare, underground facilities, or multi-story buildings, GPS signals are often blocked or jammed, leaving soldiers vulnerable. SmarTrack overcomes this challenge by using advanced RF-based distance measurement combined with secure data links. Th...
Read more »

OCCAR Awards €3.41 Billion Contract for Schakal Infantry Fighting Vehicles to Artec GmbH

-
Image
The Organisation Conjointe de Coopération en Matière d'Armement (OCCAR) has officially commissioned Artec GmbH to deliver 222 Schakal Infantry Fighting Vehicles (IFVs). This major defense contract represents a significant step in strengthening European military cooperation, particularly between Germany and the Netherlands. The Schakal program is designed to enhance the operational capabilities of both nations’ armed forces while reinforcing the role of Rheinmetall and Artec GmbH as leading players in the European defense industry. Schakal IFV. Photo: KNDS Distribution of Schakal Infantry Fighting Vehicles Under the terms of the agreement, the 222 vehicles will be distributed between two NATO allies. The German Armed Forces will receive 150 units, while the Royal Netherlands Army will take delivery of 72 units. This distribution highlights the shared commitment of both nations to modernize their land forces with advanced, mobile, and highly protected combat platforms. Contract Va...
Read more »

French Navy Receives Its First FDI Frigate Amiral Ronarc’h at Brest Naval Base

-
Image
On October 17, 2025, the French Navy reached a significant milestone with the formal handover of the first Frégate de Défense et d’Intervention (FDI) by Naval Group to the Direction générale de l’armement (DGA) in Brest. This event marked the beginning of a new era for France’s maritime defense capabilities. The ship, named Amiral Ronarc'h (D660), is the first of five units ordered to reinforce the French fleet. Stationed at Brest, the second-largest naval base on the Atlantic coast, the vessel has now entered its operational trial phase and is expected to become fully active in 2026. Photo: DGA Role and Capabilities The FDI-class frigates are designed as true multi-role combatants, capable of addressing a wide spectrum of modern naval threats. Their mission profiles include anti-air warfare (AAW), anti-surface warfare (ASuW), and anti-submarine warfare (ASW). This versatility ensures that the ships can operate independently or as part of larger task forces, providing France with ...
Read more »

Lockheed Martin Secures $233M Contract for IRST21 Block II to Boost U.S. Air Superiority

-
Image
Lockheed Martin has secured a fixed-price contract worth $233 million to supply the United States Navy and Air National Guard with the advanced IRST21 Block II system, along with initial spare parts. This agreement represents a significant step forward in enhancing the combat readiness of U.S. air forces, ensuring that both current and future generations of fighter aircraft remain capable of meeting evolving threats in modern aerial warfare. Photo: lockheedmartin.com IRST21 Block II System Capabilities The IRST21 (Infrared Search and Track) is a cutting-edge long-wave infrared sensor designed to passively detect and track airborne targets at extended ranges. Unlike radar systems, which emit signals that can be intercepted or jammed, IRST21 operates silently, making it extremely difficult for adversaries to detect. This passive capability provides pilots with a critical advantage, allowing them to identify and monitor enemy aircraft without revealing their own position. Photo: lockhee...
Read more »

Raytheon Delivers PhantomStrike Radar with Gallium Nitride (GaN) Technology to KAI for FA-50 Light Combat Aircraft

-
Image
Raytheon, a business under RTX, has officially delivered its first PhantomStrike radar system to Korea Aerospace Industries (KAI). The advanced radar will be integrated into the FA-50 Light Combat Aircraft, marking a significant milestone in enhancing the aircraft’s combat capabilities. This delivery represents not only a technological leap but also a strategic step in strengthening the global defense market presence of both Raytheon and KAI. Photo: rtx.com PhantomStrike Radar Technology Overview The PhantomStrike radar is the first of its kind in its class, utilizing Gallium Nitride (GaN) technology and operating with a fully air-cooled system. Unlike traditional fire-control radars, PhantomStrike is designed to be more efficient, lighter, and cost-effective. Its innovative design allows it to deliver advanced detection, tracking, and targeting of long-range threats while maintaining a compact and lightweight structure. This makes it particularly suitable for modern combat environme...
Read more »

AeroVironment Awarded RCCTO Contract to Deliver Kinesis Command and Control Software for HMIF Increment 1

-
Image
AeroVironment, Inc. (AV) has been awarded a significant contract by the U.S. Army Rapid Capabilities and Critical Technologies Office (RCCTO). The agreement is tied to the Human-Machine Integrated Formations (HMIF) Increment 1 program, a forward-looking initiative designed to accelerate the deployment of robotic formations on the battlefield. The primary objective of HMIF is to reduce risks faced by soldiers while simultaneously enhancing the quality and speed of decision-making in combat operations. By integrating autonomous systems into tactical formations, the Army aims to create a more resilient and adaptive force structure. Photo: avinc.com The Role of Kinesis Sofware At the heart of AeroVironment’s solution lies Kinesis, the company’s proprietary command and control (C2) software. Kinesis is designed to streamline mission planning, provide real-time tactical awareness, manage autonomous functions, and enable payload control. Its unified interface simplifies complex operations...
Read more »