World :: Worst disasters in aviation history averted seconds before impact.
Pictures have been released showing the moment an Air Canada jet came within seconds of crashing into four other passenger planes.
The incident happened after the pilots mistook a taxiway for a runway at San Francisco airport.
The images show the Airbus A320, which had 140 passengers on board, coming within 59 feet of several other jets that were moving into position to take off.
The pilots pulled up sharply when they realised how close they were to the ground, according to a National Transportation Safety Board (NTSB) report.
Air Canada flight 759 then made another approach and landed successfully.
NTSB investigators said they have not established the likely cause for the incident that could have resulted in one of the worst disasters in aviation history.
Four aircraft were waiting in a line on the taxiway at the time.
Pilots in a United Airlines plane that was among those preparing to take off saw what was happening and alerted air traffic controllers about the off-course jet.
The crew of a Philippine Airlines jet behind it switched on their plane's landing lights in an apparent last-ditch danger signal to Air Canada.
The Air Canada jet approached the taxiway just before midnight after a flight from Toronto on 7 July.
The NSTB said it was so far off course that it did not appear on a radar system designed to prevent runway collisions.
The pilots told investigators "they did not recall seeing aircraft on taxiway but that something did not look right to them".
Both the members of the flight crew were very experienced. The captain, who was flying the plane, had more than 20,000 hours of flying time. The co-pilot had about 10,000 hours.
Conversations between the pair were wiped from the aircraft's data recorder when the aircraft took subsequent flights.
Recorders are required to capture only the last two hours of a plane's flying time.
A spokesman for Air Canada declined to comment because of the ongoing investigation.