INTRODUCTION: Human factors are responsible for 80% of accidents and 50% of serious incidents. The Human Factor Analysis and Classification System allows the identification of contributing factors, including pilot preconditions, as the imminent layer prior to errors. This study aimed to investigate the association of pilot preconditions and errors to accidents and serious incidents from 2007-2024 in Indonesia. METHODS: This was a cross-sectional study design with secondary data from the investigation reports published by the National Transport Safety Committee (NTSC) from 2007-2024 in Indonesia, downloaded from the NTSC website, August 12-31, 2024. The study focused on pilot-error-related investigation reports, analyzing preconditions and errors. Internal validation was conducted with the NTSC investigators. Statistical analysis using nonparametric tests was carried out to assess the association between preconditions, errors, and incident severity (Accidents and Serious Incidents). RESULTS: A total of 245 investigation reports were downloaded, amounting to 253 aircraft, with 8 aircraft involved in near collisions, and 186 pilot-error-related investigations selected as subject analysis. The study found that pilots with Adverse Mental States had a 3.87 times higher risk [95% confidence interval (CI) = 1.77-8.47] for accidents, while pilots with Physical Mental Limitation had a 3.35 times higher risk (95% CI = 1.50-7.45). In addition, pilots with Skill-Based Errors had a 3.07 times higher risk (95% CI = 1.38-6.83) for accidents. DISCUSSION: Aviation accidents and serious incidents are caused by multiple contributing factors, and the complexity of human factors emphasizes the need for a multifaceted approach to mitigating pilot error. Yuliawati I, Sampurna B, Wiguna T, Subekti I, Kekalih A, Mustopo WI, Diatri H, Mulyawan W. Pilot preconditions and errors identified in indonesian aviation accident investigation reports. Aerosp Med Hum Perform. 2025; 96(10):911-918.