Flight MH370: The unanswered questions

The Malaysian prime minister has declared that Malaysia Airlines Flight MH370 "ended in the southern Indian Ocean", but several questions and enigmassurrounding the tragedy remain unsolved while the world waits for explanations.  [Special coverage]

Q. Why did Malaysia announce the aircraft had crashed into the southern Indian Ocean based simply on analysis of satellite data, rather than solid evidence such as authenticated debris?

A. Many people contacted by China Daily or discussing the announcement on the Internet have expressed concerns about whether the conclusion is justifiable and is based on enough evidence, given that no physical part of the aircraft has yet been retrieved.

They said the Malaysian government should provide more evidence to back up the satellite data, even though the authority of the United Kingdom's Air Accidents Investigation Branch and Inmarsat is beyond question, before reaching the conclusion.

Q. How hard is it to locate and retrieve the aircraft's two flight recorders, commonly known as "black boxes"?

A. Most experts agree that the most direct and reliable method of unearthing the real causes behind the disappearance of Flight MH370 is by analyzing information and data recorded by the black boxes.

However, no one knows exactly how long will it take and how difficult will it be to find the devices.

The signal sent out by the instruments will be significantly muffled by seawater, according to Wang Ya'nan, deputy editor-in-chief at Aerospace Knowledge magazine. He said after the 2009 crash of Air France flight 447, it took investigators nearly two years to find the recorders. Search teams failed to locate its signal because the recorder was submerged to a depth of 3,900 meters.

The ocean depth in the area suspected to be the final location of flight MH370 ranges from 2,500 to 4,000 m, according to Woods Hole Oceanographic Institution in the United States.

Q. How much effective information could be obtained from the black box?

A. Zhou Jisheng, former deputy chief designer of the ARJ21 - the Chinese-made regional jet - said: "It is very difficult to extrapolate exactly what happened during the almost eight-hour flight from the black boxes, namely the flight data recorder and the cockpit voice recorder. The memory of the cockpit voice recorder is usually only two-hours. The flight data recorder can record for at least 25 hours, but it only saves flight data."

Chen Cheng, chief editor of the website Sina's aviation channel who was a maintenance technician for Boeing 767s for five years, said: "If someone could turn off the transponder, they could also turn off the black boxes. It is not difficult for a pilot or anyone that knows the airplane well to turn off the devices."

Q. What were the real causes of the disappearance?

A. A wealth of speculation has lingered around the incident, because no one has been able to draw a complete picture of what took place in the cockpit and cabin before the Boeing 777-200 disappeared.

Many experts with knowledge of investigations into such incidents have suggested that it's highly likely that the plane's disappearance was the result of a well-planned plot, but no organization or individual has yet claimed responsibility.

Unverified claims about criminal investigations into a number of individuals continue to circulate among the public, which is eagerly awaiting a credible explanation.

Q. Why did it take the Malaysian authorities so long to release information and data held by them during the past several days, and why did they sometimes only do so after international media outlets had published related information?

A. Xu Ke, a former pilot who is now an aviation security researcher at Zhejiang Police College, said many of the Malaysian authorities' actions had taken the public by surprise and it was difficult to explain the motives behind those actions.