Final Report


On 9 December 2016, a QantasLink Bombardier DHC-8-402, registered VH-LQG (LQG) departed runway 16 left at Sydney Airport. The aircraft was operating a scheduled passenger flight from Sydney to Tamworth, New South Wales.

When LQG departed, an Air New Zealand Boeing 777-219ER, registered ZK-OKF (OKF), operating a scheduled passenger flight from Auckland, New Zealand, was on descent to Sydney.

The projected routes of the aircraft conflicted and Sydney air traffic control planned to apply vertical separation between them by assigning LQG an intermediate altitude of 5,000 ft and OKF and intermediate altitude of 6,000 ft.  LQG did not maintain 5,000 ft, reaching an altitude of 5,600 ft, and separation was not maintained between the aircraft.

The ATSB determined that the flight crew were cognisant of the requirement to maintain 5000 ft and had configured the autopilot accordingly. An unexpected autopilot mode changed occurred, before the assigned altitude was reached, and the PF decided to hand fly the aircraft until the autopilot was again correctly configured. They then attempted to reconnect the autopilot but in doing so made a mistake and the autopilot did not reconnect. The flight crew both believed the autopilot was reconnected and did not realise the mistake until after the level excursion occurred.

The incident highlights the critical nature of effective crew resource management in multi crew operations.

Aviation Short Investigations Bulletin - Issue 58

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