Description

On 10 February 2010 a Boeing 737-300 being operated by KLM on a scheduled passenger flight from Amsterdam to Warsaw, Poland took off in normal night visibility from a taxiway parallel to the runway for which take off clearance had been given and accepted - runway 36C. Because of the available distance and the absence of obstructions, the take off was completed uneventfully as was the subsequent flight.

Investigation

An Investigation was carried out by the Dutch Safety Board. There was concern that the Cockpit Voice Recorder (CVR) had continued to run after the event so that the communications relating to it had been overwritten, despite the existence of an operator procedure describing the option to trip the controlling circuit breaker during a flight. Recorded flight data was, however, available.

It was established that en route from the terminal gate to the runway, the aircraft had been de-iced on an apron specifically designated for that purpose. ATC had then given an instruction to taxi to the departure runway 36C via taxiway ‘A’ which was against prescribed direction of travel (see the diagram below) It was noted that there were two parallel taxiways adjacent to runway 36C, ‘A’ and ‘B’, with taxiway ‘A’ located furthest to the east. Whilst the aircraft was taxiing to the beginning of the runway, ATC suggested that if ready on reaching, the aircraft could take a shorter route to the take-off runway via entry W8 and this offer was accepted. Soon afterwards, the aircraft turned right on W8 and whilst between taxiway ‘A’ and taxiway ‘B’ received ‘line up and wait’ and then take off clearances in quick succession. It turned right again onto taxiway ‘B’ and after a short pause began a standing start take off.