What happened
On the night of 18 July 2018, a Malaysia Airlines Airbus A330, registration 9M-MTK, departed Brisbane Airport for Kuala Lumpur. The flight, carrying 215 passengers and 14 crew, encountered significant instrumentation errors shortly after rotation. Because covers had been left on all three pitot probes to protect against local wasp activity, the aircraft's airspeed indicators displayed red speed flags and unrealistically low values.
As the aircraft accelerated, the flight crew did not immediately react to the speed flags. By the time the discrepancy was addressed, the aircraft had reached a speed that made a safe rejected take-off impossible, forcing the crew to continue the departure. During the climb, the crew attempted to troubleshoot the issue, which eventually led to the deactivation of the air data systems. This action engaged the Back-up Speed Scale (BSS), providing the crew with essential flight envelope information. The aircraft eventually returned to Brisbane for a safe landing, though it sustained minor damage to the landing gear doors and experienced a loss of nose wheel steering.
The investigation
The investigation examined several layers of operational failure, ranging from ground handling to cockpit management. Investigators found that a support engineer had applied the pitot covers to prevent mud wasp nests but failed to communicate this to the certifying engineer. Furthermore, the pre-flight walk-around inspections, which should have identified the covers, were either omitted or performed with insufficient diligence by the ground and flight crews.
In the cockpit, the investigation analyzed the crew's response to the unreliable airspeed. It was noted that high cognitive workload, uncertainty, and a lack of assertive communication between the pilots contributed to the delayed recognition of the problem. The investigation also reviewed the effectiveness of the aircraft's alerting systems and the adequacy of the operator's risk management processes regarding the use of specialized ground equipment.
Findings
- Pitot probe covers were left on the aircraft, obstructing the airspeed sensors.
- A breakdown in communication between ground engineers and the certifying engineer prevented the identification of the covers during the turnaround.
- Pre-flight inspections were incomplete or omitted, failing to serve as a critical safety barrier.
- The unreliable airspeed was not detected early enough to allow for a safe rejection of the take-off.
- Inadequate coordination and high workload in the flight deck delayed the crew's response to the instrument flags.
- The risk management processes for managing the use of pitot covers were insufficient and failed to implement necessary controls.