Description

On 7 January 2008, a Boeing 747-400 being operated by Qantas on a scheduled passenger flight from London Heathrow to Bangkok was descending through FL100 about 13.5 nm NNW of destination in day VMC when indications of progressive electrical systems failure began to be annunciated. As the aircraft neared the end of the radar downwind leg, only the AC4 bus bar was providing AC power and the aircraft main battery was indicating discharge. A manual approach to a normal landing was subsequently accomplished and the aircraft taxied to the designated gate where passenger disembarkation took place. None of the 365 occupants, who included two heavy crew members who were present in the flight deck throughout the incident, had sustained any injury and the aircraft was undamaged.

Investigation

With the consent of the State of Occurrence, an investigation into this Serious Incident was carried out by the Australian Transport Safety Bureau (ATSB). It was established that earlier in the descent, the cabin crew had advised of a significant water leak in the forward galley area. The aircraft had been radar vectored via the BKK VOR onto a left hand downwind leg towards landing on Runway 01R.

This tracking is shown on the plan below.