SYDNEY (AP) -- As hundreds of search crews frantically scour the waters off Indonesia for AirAsia Flight 8501, a couple of ships a few thousand kilometers (miles) to the south are quietly combing another patch of ocean for perhaps the most infamous missing plane of all time -- Malaysia Airlines Flight 370.
Nearly 10 months after the Malaysian aircraft vanished on a flight from Kuala Lumpur to Beijing, not a single trace of it has been found, despite a massive, Australian-led search effort in the remote waters of the southern Indian Ocean.
While it's not yet clear what happened to either plane, Australian Prime Minister Tony Abbott warned against drawing comparisons, saying: "This is not a mystery like the MH370 disappearance ... it's an aircraft that was flying a regular route on a regular schedule, it struck what appears to have been horrific weather and it's downed."
Still, the latest disaster has focused attention once again on the frustratingly fruitless hunt for Flight 370. Here is a look at the latest in that search:
WHERE ARE THEY SEARCHING -- AND HOW?
Three ships -- two provided by a Dutch contractor and one provided by Malaysia -- have been tasked with scouring a desolate, 60,000 square kilometer (23,000 square mile) area of the Indian Ocean about 1,800 kilometers (1,100) miles west of Australia. Two of the ships have been dragging sonar devices called towfish through the water about 100 meters (330 feet) above the seabed to hunt for the wreckage. The third ship recently finished mapping the seafloor and returned to port in Western Australia last week to be fitted with search equipment.
HOW FAR HAVE THEY GOTTEN?
The ships have searched more than 12,000 square kilometers (4,600 square miles) of the seafloor -- or one-fifth of the highest-priority search zone. So far, nothing connected to Flight 370 has been found.
WHAT ABOUT FLOATING DEBRIS?
Officials believe any wreckage that may have been floating has long since sunk. Still, they did ask Indonesian authorities in August to keep an eye out for any debris that may have drifted to the island nation's shores.
HOW LONG WILL IT TAKE TO FINISH THE SEARCH?
It depends. If there are no major delays due to bad weather or issues with the equipment (and there have already been some intermittent equipment problems), the search is expected to be complete around May 2015. Otherwise, it could drag well beyond that.
SO WHAT DO OFFICIALS THINK HAPPENED?
There are a million theories. But the Australian Transport Safety Bureau, which is leading the search effort and has analyzed transmissions between the aircraft and a satellite, is working on the assumption that the plane was flying on autopilot when it ran out of fuel and crashed into the ocean. Malaysian officials heading up the investigation have previously said they believe the plane was deliberately diverted by someone on board, and its communications systems intentionally disabled.