David Learmount/LONDON

The failure by Aero Peru maintenance employees to remove protective adhesive tape placed over an aircraft's pilot/static vents during maintenance may have caused a Boeing 757 to crash on 2 October, says a Peruvian transport ministry statement (Flight International, 9-15 October).

Tape covering static vents, which provide external atmospheric pressure to sensors for the airspeed indicators and altimeters, as well as the flight-management system, has been found on a part of the fuselage recovered from the sea. Information from the recovered cockpit-voice recorder has added further confirmation to the theory.

All 70 people on board died when the aircraft crashed into the sea half an hour after leaving Lima, Peru, at night, in poor visibility. Soon after take-off, the crew requested air-traffic-control (ATC) assistance to return but, during a dialogue with ATC, the captain continually reported that he had no height, airspeed or position readouts. This meant that the crew lacked the basic flight information for an instrument return to base, given the conditions.

Tape is placed over pilot/static vents during operations such as aircraft cleaning, polishing or painting, to prevent their becoming blocked by cleaning materials or paint. The procedure of using brightly-coloured tape for this purpose is approved in Boeing's maintenance manuals, which also outline measures for its removal.

See Birgenair crash story, P15.

Source: Flight International