Investigators have concluded the Swissair Flight 111 crash was caused by a fire on board the aircraft.
All 229 people on Swissair Flight 111 perished
The fire is thought to have started when a spark from a damaged wire ignited insulation material in the in-flight entertainment system.
All 229 people on board the flight were killed when the aircraft plunged into the Atlantic in 1998.
Canada's Transportation Safety Board has published their final conclusions from an investigation which has taken more than four years and cost $30m.
"This has been the largest, most complex aviation investigation the TSB has ever undertaken," said the board's chairman Camille Theriault.
Swissair Flight 111 plummeted into the sea off Nova Scotia while en route from New York to Geneva.
'Smoke in cockpit'
Pilots reported smoke in the cockpit 53 minutes into the flight; the electrical systems began failing 13 minutes later.
The 338-page report concentrated on the in-flight entertainment system aboard the aircraft, saying a problem with wiring went unnoticed and the spark "most likely" started there.
Its recommendations include the testing of insulation materials and electrical systems and improving the flight cockpit and data recording systems.
Earlier recommendations led to flammable insulation material being removed from aircraft and improved fire procedure for pilots.
Pilots reported smoke in the cockpit
Mr Theriault added that the report would "change the face of aviation safety".
In-flight entertainment systems - which allow passengers to play games and watch videos - require large amounts of power to work them, Associated Press quoted one expert as saying.
In March 2002, a United States federal judge dismissed claims for punitive damages for families of victims of the Swissair crash.