Description

On 21 April 2006, the crew of a Boeing 737-800 (VH-VXS) being operated on a scheduled passenger flight from Brisbane to Mount Isa in normal ground visibility and daylight commenced take off in accordance with their issued clearance and then observed a vehicle crossing the runway ahead. Having assessed that it would be clear by the time their aircraft reached the crossing position, they continued and completed the take off with no actual conflict resulting.

Investigation

An Investigation was carried out by the Australian Transport Safety Bureau (ATSB) into the incident which was classified as an ‘Operational non compliance’. It was established that the 737 had entered runway 01 for take off from taxiway A7 (see the annotated diagram below). A vehicle towing an out of service 737 (Tug 41) was behind the departing 737 at A7. Another vehicle not towing an aircraft, Tug 92, was at the H4 holding point and both vehicles were waiting for clearances to cross the runway which, in accordance with local practice, would be given by the GND controller on the GND frequency. Seven seconds after the TWR controller had issued a take off clearance to the departing 737, the GND controller cleared the Tug 92 to cross the runway (from right to left as viewed by the crew of the departing aircraft) and it began to move.