Description

On 26 October 2010, a Boeing 737-800 being operated by All Nippon AW on a scheduled passenger flight from Chubu Centrair to Asahikawa in day Instrument Meteorological Conditions (IMC) was being radar vectored towards an eventual ILS approach at destination when two GPWS/TAWS PULL UP Warnings were activated in quick succession and a recovery climb made. None of the 57 occupants were injured during the occurrence and the aircraft was subsequently vectored to the destination ILS without further event.

Investigation

An Investigation was carried out by the Japan Transport Safety Board (JTSB). Cockpit Voice Recorder (CVR) data had been overwritten but DFDR and ATC R/T recordings were available and a successful download from the non volatile memory (NVM) in the TAWS unit was achieved. It was noted that although thirteen “busier” Japanese airports had been provided with Minimum Safe Altitude Warning (MSAW) prior to the investigated event, this system was not installed at Asahikawa.

It was established that the aircraft commander had been PF. It was noted that the PF had only recently qualified as a commander on the aircraft type but had some prior experience as a First Officer on the type. By contrast, the First Officer was considerably older than the PF and had accumulated a great deal more total and type flying experience.