What happened
During a solo flight operation, a pilot fell asleep while operating the aircraft. The incident occurred during a period following a five-day leave, during which the pilot had the opportunity to prepare for an upcoming night shift. Despite the availability of rest, the pilot did not successfully plan or obtain sufficient sleep prior to commencing duty. Following the initial event, the pilot continued the flight from King Island to Moorabbin without any additional rest periods.
The investigation
The investigation focused on the physiological state of the pilot and the organizational environment. Analysis determined that the pilot was very likely to be acutely fatigued at the time they fell asleep, a state driven by a lack of recent sleep and extended hours of wakefulness. The pilot did not identify fatigue as a hazard because they failed to recognize the physical signs of impairment. Furthermore, the investigation examined the operator's role, noting that the company lacked specific measures to verify the pilot's fitness to continue the shift following the incident. The investigation also looked at broader roster patterns, finding that the operator's schedules varied weekly and were often provided with short notice, making it difficult for crew to predict shifts and plan sleep cycles effectively.
Findings
- The pilot's acute fatigue was primarily caused by insufficient sleep and prolonged wakefulness.
- The pilot failed to recognize the onset of fatigue symptoms.
- The operator lacked procedures to ensure pilot fitness for duty following a fatigue-related event.
- Inconsistent and short-notice rostering practices at the operator level can hinder a pilot's ability to plan for night shift work.