What happened
Following a departure from Sydney, the flight crew failed to retract the landing gear, leaving the aircraft in an incorrect configuration for an extended period. During the initial climb, the crew's attention was primarily directed toward managing the aircraft's speed and pitch attitude. Because the crew was preoccupied with these performance parameters, the standard 'positive rate' call was omitted. This omission meant the subsequent 'gear up' command was never triggered.
As the aircraft climbed, the crew did not realize the gear remained extended. While the aircraft eventually exceeded the maximum altitude for operating with the gear down, no damage to the aircraft's serviceability occurred, and no speed limits were exceeded. The error was eventually identified after cabin crew members noticed the gear remained extended and alerted the flight deck.
The investigation
Investigators examined the crew's performance during the after-take-off checklist. During this process, the pilot flying incorrectly called out 'up, no lights' despite the landing gear handle being in the down position and the three green lights being illuminated. The pilot monitoring failed to catch this error.
It was determined that the crew's focus on maintaining speed and pitch, combined with the increased workload of the first officer hand-flying the aircraft, led to a breakdown in standard procedures. The investigation also noted that the crew experienced noise and vibration, which they mistakenly attributed to propeller balance issues rather than the extended gear. This led them to reduce climb speed, further distracting them from the configuration error.
Findings
- The omission of the 'positive rate' call removed the necessary verbal cue for the gear retraction.
- High levels of expectancy bias led the pilots to assume the gear had been retracted during the checklist.
- The crew's attention was diverted by the need to manage aircraft pitch and speed during the climb.
- The presence of three green lights was misinterpreted or overlooked due to the crew's focus on other tasks.