Malaysia has been criticized over its handling of one of the most perplexing mysteries in aviation history. Much of the most strident criticism has come from relatives of the Chinese passengers, some of whom expressed outrage that Malaysia essentially declared their loved ones dead without recovering a single piece of wreckage.
At a hotel banquet room in Beijing on Wednesday, a delegation of Malaysian government and airline officials explained what they knew to the relatives. They were met with skepticism and even ridicule by some of the 100 people in the audience, who questioned how investigators could have concluded the direction and speed of the plane. One man later said he wanted to pummel everyone in the Malaysian delegation.
"We still have hope, but it is tiny, tiny," said Ma Xuemei, whose niece was on the flight. "All the information has been confusing and unreliable."
China dispatched a special envoy to Kuala Lumpur, Vice Foreign Minister Zhang Yesui, who met Prime Minister Najib Razak.
China's support for families is likely why authorities — normally wary of any spontaneous demonstrations that could undermine social stability — permitted a rare protest Tuesday outside the Malaysian Embassy in Beijing. Relatives chanted slogans, threw water bottles and briefly tussled with police who kept them from a swarm of journalists.
Meanwhile, a U.S.-based law firm filed court documents that often precede a lawsuit on behalf of a relative of an Indonesian-born passenger. The filing in Chicago asked a judge to order Malaysia Airlines and Chicago-based Boeing Co. to turn over documents related to the possibility that "negligence" caused the Boeing 777 to crash, including any documentation about the chances of "fatal depressurization" in the cockpit.
Though officials believe they know roughly where the plane is, they don't know why it disappeared shortly after takeoff. Investigators have ruled out nothing — including mechanical or electrical failure, hijacking, sabotage, terrorism or issues related to the mental health of the pilots or someone else on board.
And finding the wreckage and the plane's flight data and cockpit voice recorders is a major challenge. It took two years to find the black box from Air France Flight 447, which went down in the Atlantic Ocean on a flight from Rio de Janeiro to Paris in 2009, and searchers knew within days where that crash site was.
The batteries on the recorders' "pingers" are designed to last 30 days. After that, the pings begin to fade in the same way that a flashlight with failing batteries begins to dim, said Chuck Schofield of Dukane Seacom Inc., a company that has provided Malaysia Airlines with pingers in the past. Schofield said the fading pings might last five days before the battery dies.
Once a general area is pinpointed for the wreckage, experts say salvagers will have to deal with depths ranging from 3,000 to 4,500 meters (10,000 to 15,000 feet).
Griffith reported from Perth, Australia. Associated Press writers Eileen Ng in Kuala Lumpur, Christopher Bodeen and Didi Tang in Beijing, Kristen Gelineau in Sydney, Rod McGuirk in Canberra, Australia, Justin Pritchard in Los Angeles, Michael Tarm in Chicago, Eric Tucker in Washington and Nick Perry in Wellington, New Zealand, contributed to this report.