F35 Crash at Eielson AFB Due to Frozen Hydraulic Fluid Causes $196 Million Loss

Frozen Landing Gear Malfunction Leads to $196.5 Million F-35 Lightning II Loss at Eielson Air Force Base

On January 28, 2025, a U.S. Air Force F-35A Lightning II crashed at Eielson Air Force Base in Alaska, marking a significant event in military aviation due to a combination of technical, procedural, and environmental failures. This incident resulted in the loss of an aircraft valued at $196.5 million and has since prompted a comprehensive investigation into the vulnerabilities of advanced fighter jets operating in extreme cold climates. The mishap not only highlighted the challenges posed by Arctic conditions but also exposed broader issues with maintenance protocols and the reliability of the F-35 fleet.

The crash, which was captured on video and widely reported, involved a cascade of failures beginning with water-contaminated hydraulic fluid freezing in the aircraft’s landing gear system. This led the flight control system to misinterpret the aircraft’s status, ultimately resulting in an uncontrollable situation. While the pilot safely ejected and survived with minor injuries, the event has sparked discussions about the readiness of the F-35 program for operations in harsh environments, as well as the importance of rigorous maintenance and decision-making processes.

Incident Overview and Timeline

The day of the accident began with routine air-to-air combat training for four F-35s from the 355th Fighter Squadron. The temperature in Fairbanks, Alaska, was close to zero degrees Fahrenheit, a critical factor in the subsequent mechanical failure. The aircraft involved was piloted by an experienced aviator with over 2,200 hours of flight experience, including substantial time on both the A-10 and F-35 platforms.

The mission’s first sign of trouble emerged after an extended period on the ground, during which the aircraft’s hydraulic fluid, already contaminated with water, had time to freeze within the nose landing gear system. After takeoff, the pilot noticed the nose gear would not retract. Attempts to extend the gear revealed it was stuck at an unsafe angle, making a normal landing impossible and eliminating the option of using Eielson’s arresting barrier system.

The pilot, accompanied by his wingman, entered a holding pattern while ground crews and Manufacturers and Lockheed Martin engineers joined a 50-minute conference call to troubleshoot the issue. The consensus was to attempt touch-and-go landings to realign the nose wheel. The first attempt failed; the second, conducted at higher speed, resulted in ice buildup spreading to both main landing gear struts. This triggered a catastrophic flight control failure, as sensors incorrectly indicated the aircraft was on the ground, causing the jet to enter an uncontrollable mode and forcing the pilot to eject.

Technical Analysis: Flight Control System and Sensor Failures

The F-35 employs advanced automated flight control systems with multiple modes, including those for takeoff, landing, and ground operations. These modes rely on the Weight on Wheels (WoW) sensors, mechanical switches that detect the compression of landing gear struts to determine whether the aircraft is airborne or on the ground.

In this incident, the freezing of water-contaminated hydraulic fluid prevented the landing gear from fully extending, causing the WoW sensors to falsely register that the aircraft was grounded. As a result, the flight control system switched to “on ground” mode while the aircraft was still airborne at over 250 miles per hour and 372 feet above the runway. This mode, intended for taxiing and ground handling, rendered the jet uncontrollable in flight.

Lockheed Martin had previously identified risks associated with WoW sensor malfunctions, especially in cold weather. Maintenance bulletins had warned that unresolved WoW faults could lead to erratic flying qualities and controllability issues. However, these warnings were not fully integrated into the emergency decision-making process during the incident.

“Not acting on a WoW switch fault could result in WoW switches faulting on a future flight which can cause erratic flying qualities making it difficult for the pilot to maintain control of the aircraft.”

— Lockheed Martin newsletter, April 2024

Maintenance and Procedural Breakdown

The investigation found that the root cause of the failure was water-contaminated hydraulic fluid, estimated at around 30 percent, well above acceptable levels. This contamination likely occurred due to improper storage and handling of hydraulic fluid barrels, which had been exposed to humid conditions during deployments and were inadequately tracked and supervised.

The 355th Fighter Generation Squadron lacked a dedicated hazardous materials manager, and critical documentation was missing or incomplete. Maintenance personnel used a hand cart instead of a nitrogen servicing cart and failed to flush lines properly, further increasing the risk of contamination. Both the barrel and servicing cart used for the mishap aircraft tested at more than double the acceptable particulate limits.

Alarmingly, a nearly identical hydraulic system problem occurred on another F-35 at Eielson just nine days later. In that case, the pilot landed safely, but the recurrence underscored systemic issues in maintenance discipline and procedural compliance.

Historical Context and Fleet Reliability

The Eielson crash is the 15th recorded F-35 incident since the aircraft’s introduction. The F-35 program, initiated in 1995, has delivered nearly 1,100 aircraft globally but has faced a series of setbacks ranging from engine fires to system malfunctions and pilot disorientation events.

According to the Director of Operational Test and Evaluation, the F-35 fleet’s availability rate stands at 51 percent, significantly below the target of 65 percent. This rate has declined since 2021, reflecting ongoing reliability and maintenance challenges. The F-35A variant achieves only 10.5 mean flight hours between critical failures, compared to the required 20 hours, and repair times for mission-critical failures routinely exceed operational requirements.

The Government Accountability Office has highlighted persistent supply chain issues and maintenance delays, with up to 27 percent of the fleet grounded due to supply problems and an additional 15 percent down for maintenance as of September 2023. These challenges have prompted congressional scrutiny and ongoing efforts to improve mission capability rates.

“The operational suitability of the F-35 fleet remains below service expectations and requirements.”

— Director of Operational Test and Evaluation, 2023 Annual Report

Financial Impact and Cost Analysis

The loss of the F-35A at Eielson represents a direct financial hit of $196.5 million, making it one of the most expensive single-aircraft losses in Air Force history. This figure covers only the replacement cost of the jet and does not account for investigation, cleanup, or operational disruption expenses.

The F-35 program is the most expensive weapons system in U.S. history, with a projected lifetime cost exceeding $1.7 trillion. Each aircraft loss reduces the return on this massive investment and impacts fleet readiness, training, and support infrastructure.

The incident also necessitated a fleet-wide review of hydraulic fluid handling and maintenance practices, adding indirect costs related to corrective actions and operational delays. The recurrence of similar problems in other aircraft suggests that the financial impact of maintenance failures could be far-reaching.

Broader Implications for Arctic Operations

The Eielson crash underscores the unique challenges of operating advanced Military-Aircraft in Arctic environments. Extreme cold can compromise systems that function reliably in milder climates, as evidenced by the F-35’s hydraulic and sensor failures in Alaska. Previous incidents at Eielson have also involved cold-induced battery heating problems and false alarm triggers.

As geopolitical competition intensifies in the Arctic, reliable air power is crucial for U.S. strategy. Eielson AFB is a key hub for projecting force in the region, and any vulnerability in its F-35 fleet could have strategic consequences. The incident has prompted a reassessment of maintenance procedures, storage protocols, and cold-weather adaptations for F-35 operations.

Allied nations operating F-35s in similar climates, such as Norway, are likely to review their own practices in light of the Eielson findings. Norway, for instance, has equipped its F-35s with drag chutes for icy runways, a modification not present on U.S. models. The lessons from Eielson may drive further modifications and procedural changes across the global F-35 community.

Lessons Learned and Decision-Making Analysis

The 50-minute conference call between the pilot, ground crew, and Lockheed Martin engineers was both a testament to real-time technical collaboration and a case study in decision-making under pressure. While the team made a good-faith effort to resolve the emergency, the chosen course of repeated touch-and-go attempts failed to account for the risks of cascading sensor failures.

Lockheed Martin’s prior guidance on WoW sensor risks was available to the engineering team but was not fully integrated into the crisis response. The investigation concluded that a planned full-stop landing or controlled ejection might have prevented the loss, had the broader risks been considered.

The incident highlights the need for comprehensive emergency procedures that address the complex interactions between mechanical, environmental, and software systems in highly automated aircraft like the F-35. The recurrence of similar hydraulic problems shortly after the crash suggests that systemic improvements in maintenance discipline and decision-making protocols are urgently needed.

Conclusion

The Eielson F-35 crash was the result of a preventable chain of failures, from maintenance lapses and environmental challenges to system design vulnerabilities. The event exposed critical weaknesses in both the aircraft’s technical systems and the organizational processes meant to safeguard them. While the pilot survived, the loss of a $196.5 million asset and the subsequent revelations about fleet-wide maintenance discipline have prompted a reevaluation of F-35 readiness for Arctic operations.

Moving forward, the Air Force and its partners must implement lessons learned from this incident, including improved maintenance protocols, enhanced training, and revised emergency procedures tailored to the realities of extreme environments. As the F-35 continues to serve as a cornerstone of U.S. and allied air power, ensuring its reliability under all operational conditions is both a matter of financial responsibility and national security.

FAQ

What caused the F-35 crash at Eielson Air Force Base?
The crash was caused by water-contaminated hydraulic fluid freezing in the landing gear system, which led to sensor failures and the flight control system incorrectly switching to ground mode while airborne.

How much did the incident cost?
The direct loss was $196.5 million for the destroyed aircraft, not including investigation, cleanup, or operational disruption costs.

Are there broader issues with F-35 reliability?
Yes. The F-35 fleet has experienced recurring reliability and maintenance challenges, with only 51% of aircraft available for operations compared to a 65% target.

What changes are being considered after the crash?
The Air Force is reviewing maintenance protocols, storage procedures, and emergency decision-making processes, especially for operations in extreme cold climates.

Have similar incidents occurred elsewhere?
Yes. Another F-35 at Eielson experienced similar hydraulic issues just nine days later, though it landed safely. Other cold weather-related failures have also been reported in Alaska.

Sources

• Alaska Public Media
• Air Force Magazine
• Defense News