Overview
- The Japan Air Self-Defense Force, in a report released Friday, said an engine part installed incorrectly during 2021 maintenance led to a thrust loss that brought down an F-2 on August 7, 2025, and the pilot ejected safely.
- Investigators detailed a failure chain in which a small pin inside the engine came loose, disturbed airflow, triggered heavy vibration, cracked compressor blades, and cut thrust so the jet could not maintain level flight.
- The error dates to around December 2021, and later inspections did not detect it because procedures were informal and records were incomplete.
- The engine was moved among five F-2s over about three years and seven months, which made the maintenance trail harder to track as fatigue built up.
- The JASDF said it will consider codifying inspection steps, improving record-keeping, and using checklist-based maintenance to prevent a repeat.