BACKGROUND: Unexpected events in flight might decrease the transparency of the flying process and weaken the pilot's perception of the current state, or even erode manipulating skills. However, during the flight test of a new or modified aircraft, to verify the boundaries of aircraft aerodynamic performance and handling stability, unexpected events may be encountered that need to be handled by the test pilot. Therefore, studying the differences between test pilots and airline pilots could help improve flight safety.METHODS: Two kinds of physiological parameters, eye blink rate and average fixation duration and task-related performance of test pilots and airline pilots, were analyzed in three abnormal scenarios. A total of 16 pilots participated. The study was carried out in an A320 flight simulator.RESULTS: The differences were significant for both test pilots and airline pilots in eye blink rate and average fixation duration. Furthermore, the reaction time of test pilots (Mean = 23.38 s) was significantly shorter than airline pilots (Mean = 42.63 s) in Unreliable Airspeed condition, and the pitch angle deviations between them were significant in both Wind Shear and Unreliable Airspeed condition.DISCUSSION: The uncertainty of environmental change could create more severe pressure and mental workload influence than actual system failure. For airline pilots, compared with test pilots, the importance of practicing manual flight should still be emphasized. Improving reactions to unexpected ambient conditions and unannounced fault status could also contribute to flight safety.Zheng Y, Lu Y, Jie Y, Zhao Z, Fu S. Test pilot and airline pilot differences in facing unexpected events. Aerosp Med Hum Perform. 2023; 94(1):18-24.