The disappearance Sunday of AirAsia Flight 8501 was the third air incident this year involving Malaysia, where budget carrier AirAsia in based. Here's a look at the two other disasters, as well as the latest missing flight, which went missing with 162 people aboard less than an hour after taking off from Surabaya, Indonesia, for Singapore.
MALAYSIA AIRLINES FLIGHT 370
The disappearance of the Malaysia Airlines Boeing 777 on March 8 triggered one of modern aviation's most perplexing mysteries. Flight 370, carrying 239 people from Kuala Lumpur to Beijing, vanished without a trace, sending searchers across vast areas of the Indian Ocean. An initial multinational operation to locate the wreckage far off Australia's west coast turned up empty, without a single piece of debris found.
After a four-month hiatus, the hunt resumed Oct. 4 with new, more sophisticated equipment, including sonar, video cameras and jet fuel sensors aboard three ships that will spend up to a year in a desolate stretch of the sea, about 1,800 kilometers (1,100 miles) west of Australia.
The 60,000-square-kilometer (23,000-square-mile) search area lies along what is known as the "seventh arc" — a stretch of ocean where investigators believe the aircraft ran out of fuel and crashed, based largely on an analysis of transmissions between the plane and a satellite.
Officials initially ruled out terrorism, but conspiracy theories have endured. Until the wreckage is found and examined, it will be impossible to say for sure what happened to the plane. (Read more on special coverage)
MALAYSIA AIRLINES FLIGHT 17
All 298 passengers and crew aboard Malaysia Airlines Flight 17 were killed when the Boeing 777 was shot down over rebel-held eastern Ukraine on July 17.
The plane was flying from Amsterdam to Kuala Lumpur when, according to Dutch air crash investigators, it was likely struck by multiple "high-energy objects" that some aviation experts say is consistent with a missile strike.
Hunks of the wreckage were transported to the Netherlands by trucks and will be reassembled in a hangar. However, international teams seeking to retrieve remains and salvage evidence have had difficulty reaching the crash site due to clashes between Ukrainian government troops and Russian-backed separatist rebels. Six victims have yet to be identified.
A high-ranking rebel officer has acknowledged that rebels shot down the plane with a ground-to-air missile after mistaking it for a Ukrainian military plane. Russian media, however, claim the plane was shot down by a Ukrainian jet.
The Dutch Safety Board's final report may rule out one or the other scenario, but it will not seek to attribute responsibility.
Dutch prosecutors, meanwhile, are coordinating an international criminal investigation into the downing, but have yet to name any suspects or say when or how charges might be brought. (Read more on special coverage)
AIR ASIA FLIGHT 8501
An Indonesia AirAsia flight with 162 people aboard, most of them Indonesians, disappeared Sunday over the Java Sea, triggering a search involving several Southeast Asian nations.
Contact with Flight 8501 was lost about 42 minutes after the single-aisle, twin-engine A320-200 jet took off from Surabaya airport in Indonesia for Singapore.
It was not immediately clear whether it had any satellite tracking devices on board.
Malaysia-based AirAsia, led by Malaysian businessman Tony Fernandes, has dominated cheap travel in the region for years. AirAsia Malaysia owns 49 percent of its subsidiary, AirAsia Indonesia. It said the plane was on the submitted flight plan route when the pilots requested deviation due to weather before communication was lost.
AirAsia, which has a presence in most of Southeast Asia and recently in India, has never lost a plane before and has a good safety track record.