What do Air Force mishap reports say about weather-related F-35 incidents in Alaska since 2018?
Executive summary
The Air Force’s Accident Investigation Board (AIB) for the Eielson AFB crash on January 28, 2025, attributes the mishap to hydraulic fluid contaminated with water that froze in the landing-gear struts, causing an automated system to command a “ground” configuration while the jet was airborne and leading to loss of control and the jet’s destruction; the pilot ejected safely [1] [2] [3]. The reports identify cold Alaskan temperatures as the proximate environmental factor interacting with maintenance and hazardous-material storage lapses, and they note at least one similar, non-catastrophic event in the same squadron days later [1] [4].
1. The documented chain: water in hydraulic fluid froze, landing gear iced, flight-control logic misinterpreted the condition
The unclassified PACAF AIB and subsequent press coverage make a clear causal chain: water-contaminated hydraulic fluid froze in the nose and main landing-gear struts in sub-zero conditions, the gear did not extend properly, the F-35’s avionics switched to a ground mode because sensors indicated a weight-on-wheels condition, and with the jet actually airborne it became uncontrollable and crashed [1] [2] [3]. Investigators explicitly concluded the immediate technical cause was hydraulic fluid contaminated by water that froze inside the landing-gear struts [5] [6].
2. Weather was the trigger, but maintenance and storage practices were the enabler
While sub-zero temperatures at Eielson provided the physical environment for water to freeze, the AIB report highlights human and logistic contributors: investigators could not conclusively determine when water entered the struts but identified likely contamination during prior deployments where hydraulic barrels were stored outdoors and exposed to humid or inclement conditions, pointing to lapses in hazmat discipline, recordkeeping and storage procedures [2] [6]. PACAF’s report also notes that brief ground operations between heated shelters and takeoff in colder conditions increased the chance that trapped water would freeze before takeoff—an operational nuance linking weather and maintenance timing [1].
3. The software/automation dimension: sensors and “ground mode” risk in cold conditions
The mishap report underscores how the F-35’s automated logic can be misled by abnormal sensor inputs: ice within the strut altered sensor readings so the aircraft’s flight control system believed it was on the ground and transitioned modes in-flight, rendering control ineffective [7] [8]. The AIB and several outlets noted existing Lockheed Martin guidance about sensor and landing-gear issues in extreme cold that had been published in April 2024, and questioned whether ground teams fully considered that guidance during the event [8] [4].
4. Patterns and near-misses: another aircraft experienced the same issue days later
The AIB reported a similar hydraulic-icing problem in another F-35 from the same base nine days after the crash; that jet was able to land safely, which the report uses to illustrate both the recurrent risk and the thin margin between recoverable and catastrophic outcomes in frigid environments [4] [1]. PACAF’s documentation also indicates sorties flown in milder temperatures earlier had not produced the malfunction, reinforcing the temperature-dependent nature of the hazard [1].
5. What the reports do not show (and reporting limits)
Open AIB materials and the press reporting focus centrally on the January 28, 2025 Eielson mishap and closely related events; they do not catalogue a series of separate, weather-related F-35 incidents across Alaska back to 2018 in the provided sources, so there is no basis in these documents to assert a longer-term Alaska-specific weather-mishap trend beyond the Eielson case and the near-miss nine days later [1] [4]. Broader accounts note multiple F-35 mishaps globally and since 2018, but those sources do not attribute other Alaska crashes to weather in the material supplied here [5] [9].
6. Implications and contested narratives
The AIB’s findings place the crash at the intersection of environment, maintenance practice, and automated systems—framing it as preventable with stricter hazmat control, adherence to guidance and possibly software or procedural mitigations for extreme cold [2] [8]. Some coverage emphasizes the aircraft’s broader safety record to raise alarm, while the AIB confines conclusions to specific technical and procedural failures; both angles are present in the sources and reflect different agendas—oversight and accountability versus program-defense and contextualization of risk [5] [3] [6].