What happened
During preparations for a scheduled flight from Brisbane Airport, Queensland, to Singapore Changi Airport, a Singapore Airlines Airbus A350-941 was being readied for departure. While the aircraft was being prepared, a refueller working at an adjacent bay noticed that the pitot probe covers had not been removed. The refueller alerted the licensed aircraft maintenance engineer (LAME) in charge of the turnaround, allowing the covers to be stripped just before the aircraft was pushed back.
The investigation
Investigators examined the maintenance procedures and the actions of the ground crew. It was found that while a procedure existed to ensure covers were removed—including a warning placard on the flight deck and a technical log entry—the LAME had assumed the covers were gone rather than verifying it visually. The LAME removed the warning placard and signed off the log entry despite the covers remaining on the aircraft. Furthermore, the aircraft maintenance engineer (AME), who was new to the organization, had been instructed not to remove covers without direction, and no such instruction or verification was provided by the LME.
CCTV footage confirmed that the final walk-around inspection, which serves as the last opportunity to detect such errors, was not performed. The AME removed the chocks but did not complete the full inspection, and the LAME did not conduct a check, assuming the task had been handled by the AME.
Findings
- The LAME certified the removal of the pitot covers in the technical log without any visual or verbal confirmation.
- The failure to implement a robust tool control procedure meant that the transit toolbox was only checked at the end of a shift rather than before aircraft dispatch.
- The LAME was managing dual roles as a regional manager and engineer, leading to an increased risk of fatigue-related errors.
- The company did not track work hours for personnel in dual management and operational roles for fatigue management purposes.
- The pitot cover streamers provided limited visibility due to their length, position, and lack of movement in the wind.
- A lack of thorough pre-flight walk-around inspections by flight crews was also noted as a contributing factor to the risk environment.