PETALING JAYA - The search for Malaysian Airlines MH370 is the longest yet for a commercial flight that has gone missing, and there is still no end in sight.
Flight MH370 took off from KL International Airport at around 12.41am bound for Beijing on March 8, but dropped off the radar soon after take off, leaving authorities struggling to piece together where the aircraft went.
As the search enters its 13th day on Thursday, it has gone past the previous record for a missing commercial airliner, when wreckage for Adam Air Flight 574 was not found until 10 days after it lost contact with air traffic control.
Flight 574, a Boeing 737-400, went missing off the coast of Indonesia's South Sulawesi on Jan 1, 2007.
The first confirmed discovery was by a fisherman who found piece of the plane's tail fin, which had serial numbers matching the missing plane. He received reward of 50mil rupiah (RM14,500) for his discovery.
Where MH370 differs from other instances is the flight path - while most followed the original planned one, the situation is not as clear-cut in MH370's case.
The search for MH370 is now along two corridors, with an area of 2.24 million square nautical miles - an area larger than Australia, which only makes search and rescue efforts even more difficult.
Here are some instances of commercial airliners that did not reach their scheduled destinations, and the search operation to find them.
Adam Air Flight 574: 10 days
On Jan 1, 2007, Adam Air Flight 574, scheduled domestic passenger flight between the Indonesian cities of Surabaya and Manado crashed into the Makassar Strait near Polewali in Sulawesi.
All 102 people on board died, the highest death toll of any aviation accident involving a Boeing 737-400.
A full national investigation was immediately launched into the disaster. The final report, released on 25 March 2008, concluded that the pilots lost control of the aircraft after they became preoccupied with troubleshooting the inertial navigation system and inadvertently disconnected the autopilot.
The black boxes were located on Jan 21, 2007.