A deadly combination of poor weather and the lack of a key guidance system was the most likely cause of the Korean Air jumbo crash, according to experts.
The Boeing 747 plunged into the side of a hill covered in dense jungle amid high winds and lashing rain in pitch darkness. The pilot was also flying without part of his landing system - known as a glide scope - which would have kept the plane above the peaks surrounding Guam's airport.
Flying experts said that the pilot has to accept some of the responsibility for the crash. "He was the captain and he should not have got there in the first place," said Captain Eric Moody, a former pilot with British Airways and a technical expert with the pilot's union, Balpa.
Capt Moody said that even if the pilot had not taken the normal landing path there are "beacons posted around airstrips which guide a plane down from thousands of feet".
David Learmount, safety editor with Flight International, pointed out that pilots can follow a simple rule of thumb to land at airports without a complicated guidance system. "It is simple. Just drop 300 feet for every mile off a runaway you find yourself. Of course, the visibility may have been so bad that he may not have seen the airstrip lights even if he was only a mile away."
Mr Learmount said that the crash would be classified as "controlled flight into terrain" - crashes that occur when a perfectly serviceable aircraft hits the ground because its crew were unaware they were flying so low.
Early reports that there may have been an explosion on board the flight before it hit the side of the mountain were dismissed.
The plane which usually flies the Seoul-Guam route is an Airbus A300, and the Boeing 747 is laid on only during the peak season. There is speculation that the jumbo pilot's inexperience with the approach to Guam might have contributed to the disaster.
The crash was Korean Air's first since 1989, but the company's accident rate is relatively high. Marty Salfen, senior vice president of the International Airline Passengers' Association, said the airline had an accident rate of 1.91 per million departures over the past 10 years against the worldwide rate of 0.581 per million. That figure does not include the loss of KAL flight 007 that strayed into Soviet airspace in 1983 and was shot down.
The cause of the crash will become clearer after the digital flight data recorder and the cockpit voice recorder are analysed. Both have been recovered and are being shipped to Washington DC for analysis by the US National Transportation Safety Board.