On 15 July 2015, Virgin Australia International was operating a Boeing 737-800, registered VH‑YIU, on a flight from Christchurch, New Zealand, to Brisbane, Queensland. The captain was the pilot flying and the first officer (FO) was the pilot monitoring. The flight was delayed, and due to depart Christchurch at 0815 New Zealand Standard Time (NZST).

The FO arrived at the airport at about 0700 and checked the flight plan package – including the flight plan, weather and notices to airmen (NOTAMs), ordered the fuel for the flight, and proceeded to the aircraft. The FO had noticed two NOTAMs dealing with runway works at Christchurch, but assessed that neither NOTAM would affect the flight. The captain arrived in Christchurch at about 0730 and proceeded directly to the waiting aircraft.

The FO used the 24K thrust rating/flaps 5 take-off reference data from the runway 02/A6 intersection table in the operator’s Airport Analysis Manual (AAM), anticipating that the full length of the runway would be available.

The captain did not read the NOTAMs but the FO advised that there was nothing significant. At about 0815, as the aircraft pushed back from the gate, air traffic control (ATC) advised the crew that runway 02 was operating at a reduced length. The reduction in runway length was associated with works in progress (WIP) that reduced the runway length available from 3,288 m to 1,920 m, with the northern 1,368 m of runway closed.

In the absence of reduced runway length data available in the AAM, the crew elected to use full thrust 26K (full thrust)/flaps 5 take off, runway threshold, reference data from the AAM that was based upon the full length of the runway being available. During taxi and while lining up on the runway, the crew did not see any personnel, equipment or obstructions on the runway. At 0827, the aircraft departed without incident.

Following departure, the captain reviewed the NOTAMs and found that the runway length at the time of their departure was reduced to 1,920 m due to WIP. The captain also noticed that there was an associated relevant company remark regarding a requirement to request On-Board Performance Tool (OPT) take-off reference data during works in progress. The crew requested the OPT take-off reference data, which revealed that different take-off reference speeds have should been used under those circumstances.

The operator’s investigation found that the ability to reject the take-off or maintain obstacle clearance safely in the event of an engine failure was compromised by the use of the incorrect take-off reference speeds. Inaccurate take-off reference data has potentially serious consequences. ATSB Aviation Research and Analysis Report AR-2009-052 (Take-off performance calculation and entry errors: A global perspective) documents a number of accidents and incidents where take off performance data was inaccurate.


Aviation Short Investigations Bulletin Issue 46

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