MH370
The disappearance of Malaysia Airlines Boeing 777 on March 8 triggered one of modern aviation's most perplexing mysteries. Flight 370 with 239 people aboard from Kuala Lumpur to Beijing vanished without trace, sending searchers across vast areas of the Indian Ocean. An initial multi-national operation to locate the wreckage far off Australia's west coast turned up empty-handed, 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 1,100 miles west of Australia.
The 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.
MH17
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 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.
QZ8501
An Indonesia AirAsia flight with 162 people aboard, most of them Indonesians, disappeared on Sunday over the Java Sea, triggering a search involving several Southeast Asian nations.
The contact with Flight 8501 was lost about 42 minutes after the single-aisle, twin-engine A320-200 jetliner took off from Surabaya airport in Indonesia for Singapore.
It is not clear if it has any satellite tracking devices on board.
Malaysia-based AirAsia, owned 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 that 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.
