Canadian investigators probing the 1998 crash of a Swissair jet in which all 229 people on board died have called for tougher tests on the electrical wiring used in commercial airplanes.
Issuing new safety recommendations in the wake of the crash off the coast of Nova Scotia, the Transportation Safety Board of Canada said more should be done to prevent sparks or wiring problems turning into fatal fires.
The new recommendations called for more stringent tests on electrical wires, stricter flammability standards on materials used in aircraft construction, and a new evaluation of systems such as air conditioning that can feed oxygen to onboard fires.
A fire in the ceiling near the cockpit of Swissair Flight 111 is believed to have caused the crash, but safety investigators still do not know what caused the fire. The pilot had reported smoke in the cockpit about 53 minutes after leaving New York on a flight to Geneva.
The plane's electrical systems began failing around 15 minutes later and the plane plunged into the Atlantic Ocean before the pilot could land in Halifax, Nova Scotia.
"A specific spark, whatever the location, should not bring down an airplane with 229 people on board," said Daniel Verreault, the board's director of investigations. "There should be defences in place to prevent this, and that is an objective that we have and that is the way that we believe we can contribute to advancing aviation safety."
Canadian investigators, who expect to release their final report next year, have examined more than two million pieces of wreckage recovered from the Atlantic seabed in their search to determine exactly what went wrong.
The SFr55 million investigation has focused to a large extent on the 250 kilometres of wiring running through the plane.
swissinfo with agencies