Description

On 2 October 1996, a Boeing 757-200 being operated by Aero Peru on a scheduled passenger flight at night from Lima to Santiago experienced control difficulties because of incorrect flight instrument readings. A return to Lima was attempted but when control was lost the aircraft impacted the sea and all 70 occupants were killed.

Investigation

An Investigation was carried out by an Accident Investigation Board made up of personnel from the Peruvian General Directorate of Air Transport (DGTA). Flight Data Recorder (FDR) and Cockpit Voice Recorder (CVR) data was recovered to assist the Investigation. After establishing that the apparently malfunctioning altimeters and airspeed indicators (ASIs) had been serviceable, it was quickly concluded that the problem with these instruments had been the result of a failure at any time before the night departure to see that all the static ports were still taped-over after release for the flight from maintenance.

The CVR confirmed that the First Officer had acted as PF for the departure. It was noted that the flight crew were experienced in proportion to age and that neither were new to the aircraft type. Post accident testing confirmed that the radio altimeters and relevant aircraft alerting systems including the Stall Protection and GPWS/TAWS had been in normal working order.