The Chinese ambassador to Malaysia announced Tuesday that China has launched a new search effort in its territory for the missing Malaysia Airlines flight amid growing uncertainty about when a key communications system was disabled on the Boeing 777.
Reports by Chinese media quoted the ambassador, Huang Huikang, as saying search operations were taking place inside China along the northern route investigators believe the plane may have traveled, The Wall Street Journal reported . Details on the search were not immediately available.
"Factors involved in the incident continue to multiply, the area of search-and-rescue continues to broaden, and the level of difficulty increases, but as long as there is one thread of hope, we will continue an all-out effort," China Premier Li Keqiang said.
The search for Flight 370, which vanished early March 8 while flying from Kuala Lumpur to Beijing with 239 people on board, has now been expanded deep into the northern and southern hemispheres. Australian vessels scoured the southern Indian Ocean and China offered 21 of its satellites to help Malaysia in the unprecedented hunt, but no trace of the plane has been found.
Malaysian Transport Minister Hishammuddin Hussein said that the search area in the northern and southern "corridors" totals 2.24 million square nautical miles (nearly 3 million square miles), about the size of Australia. Twenty-six countries are involved in the hunt.
“We know the United States has got possibly the best ability to assist us in locating the aircraft in the southern corridor,” Hussein told reporters Tuesday, according to The Guardian. Hussein said he asked U.S. Defense Secretary Chuck Hagel for help in the search efforts.
The vast scope of the search was underlined when a U.S. destroyer that already has helped cover 15,000 square miles of water dropped out.
The Navy concluded that long-range aircraft were more efficient in looking for the plane or its debris than the USS Kidd and its helicopters, so effective Tuesday the ship was leaving the Indian Ocean search area, said Navy Cmdr. William Marks, spokesman for the 7th Fleet. Navy P-3 and P-8 surveillance aircraft remain available, and can cover 15,000 square miles in a nine-hour flight.
Marks said finding the plane was like trying to locate a few people somewhere between New York and California.
Over the weekend, Prime Minister Najib Razak said investigators determined that a satellite picked up a faint signal from the aircraft about 7 1/2 hours after takeoff. The signal indicated the plane would have been somewhere on a vast arc stretching from Kazakhstan in Central Asia to the southern reaches of the Indian Ocean. The southern Indian Ocean is the world's third-deepest and one of the most remote stretches of water, with little radar coverage.
Indonesia focused on Indian Ocean waters west of Sumatra, air force spokesman Rear Marshall Hadi Tjahjanto said. Australia agreed to Malaysia's request to take the lead in searching the southern Indian Ocean with four Orion maritime planes that would be joined by New Zealand and U.S. aircraft, Australian Prime Minister Tony Abbott said.
Malaysia’s government also reportedly has asked countries to re-examine military and satellite radar data in the search for the missing plane, accusing officials of not being fully transparent in their findings.
“The only one out in the open is Malaysia,” Hussein said Tuesday, according to The Guardian.
Thailand's military said Tuesday that its radar detected a plane that may have been Malaysia Airlines Flight 370 just minutes after the jetliner's communications went down, and that it didn't share the information with Malaysia earlier because it wasn't specifically asked for it.
Air force spokesman Air Vice Marshal Montol Suchookorn said the Thai military doesn't know whether the plane it detected was Flight 370.
Montol said that at 1:28 a.m., Thai military radar "was able to detect a signal, which was not a normal signal, of a plane flying in the direction opposite from the MH370 plane," back toward Kuala Lumpur. The plane later turned right, toward Butterworth, a Malaysian city along the Malacca strait. The radar signal was infrequent and did not include any data such as the flight number.
Thailand's failure to quickly share possible information about the plane may not substantially change what Malaysian officials now know, but it raises questions about the degree to which some countries are sharing their defense data.
When asked why it took so long to release the information, Montol said, "Because we did not pay any attention to it. The Royal Thai Air Force only looks after any threats against our country." He said the plane never entered Thai airspace and that Malaysia's initial request for information in the early days of the search was not specific.
"When they asked again and there was new information and assumptions from (Malaysian) Prime Minister Najib Razak, we took a look at our information again," Montol said. "It didn't take long for us to figure out, although it did take some experts to find out about it."
Had the plane gone northwest to Central Asia, it would have crossed over countries with busy airspace. Some experts believe it more likely would have gone south, although Malaysian authorities are not ruling out the northern corridor and are eager for radar data that might confirm or rule out that route.
The northern corridor crosses through countries including China, India and Pakistan -- all of which have said they have no sign of the plane.
Jonathan Gilliam, a former member of the FBI’s Joint Terrorism Task Force, a retired Navy SEAL and a former federal air marshal, said on “Fox & Friends” Tuesday that the disappearance of the plane highlights issues with regulations in the airline industry.
“I think it already is verified or mandated that you're telling somebody that 'this is the course we are going' and 'this is the course to stay on,’” he said. “But I think there is less regulation once you get over areas where there is no radar, and that’s a big issue.”
The New York Times reported that the mysterious turn that diverted the missing flight off of its scheduled route to Beijing was programmed into a computer system on board, meaning it was not executed manually by one of the pilots at the controls.
Senior American officials told the newspaper that someone entered a code into a knee-high pedestal between the pilot and co-pilot.
The revelation lends more credence to a theory by investigators searching for the jet that the Boeing 777 was deliberately diverted. The Times reports it is unclear if the change in course was reprogrammed before or after the plane took off, but the change was likely made by someone in the cockpit with knowledge of airplane systems.
Investigators say the jet flew off-course for hours. They haven't ruled out hijacking, sabotage, or pilot suicide, and are checking the backgrounds of the 227 passengers and 12 crew members -- as well as the ground crew -- for personal problems, psychological issues or links to terrorists.
China's state news agency reported Tuesday that background checks on all its nationals on board the missing Malaysian jetliner uncovered no links to terrorism. Xinhua said the Chinese ambassador to Malaysia made the announcement to media in Kuala Lumpur.
The finding dampens speculation that Uighur separatists in China's far western Xinjiang province might have been involved with plane's disappearance.
Malaysian Airlines CEO Ahmad Jauhari Yahya said an initial investigation indicated that the last words ground controllers heard from the plane -- "All right, good night" -- were spoken by the co-pilot, Fariq Abdul Hamid. A voice other than that of Fariq or the pilot, Zaharie Ahmad Shah, it would have been clearest indication yet of something amiss in the cockpit before the flight went off-course.
Malaysian officials had said those words came after one of the jetliner's data communications systems -- the Aircraft Communications Addressing and Reporting System -- had been switched off, suggesting the voice from the cockpit may have been trying to deceive ground controllers.
However, Ahmad said that while the last data transmission from ACARS -- which gives plane performance and maintenance information -- came before that, it was still unclear at what point the system was switched off, making any implications of the timing murkier.
The new information opened the possibility that both ACARS and the plane's transponders, which make the plane visible to civilian air traffic controllers, were turned off at about the same time. It also suggests that the message delivered from the cockpit could have preceded any of the severed communications.
Turning off a transponder is easy and, in rare instances, there may be good reason to do so in flight -- for example, if it were reporting incorrect data.
Authorities have pointed to the shutdown of the transponders and the ACARS as evidence that someone with a detailed knowledge of the plane was involved. However, Bob Coffman, an airline captain and former 777 pilot, told the Associated Press that kind of information is not hard to find in the digital age.
Meanwhile, frustrated relatives of passengers on board the missing plane threatened to go on a hunger strike if they aren’t given more information on the jetliner’s whereabouts.
"What we want is the truth. Don't let them become victims of politics,” one woman at a hotel in Beijing told The Telegraph .
Yahya said his company is doing “all that [it] can to ensure that we are giving sufficient assistance, information and care to all the family members in Beijing,” according to The Guardian.
The area being covered by the Australians is even bigger -- 600,000 square kilometers (232,000 square miles) -- and will take weeks to search thoroughly, said John Young, manager of Australian Maritime Safety Authority's emergency response division.
"This search will be difficult. The sheer size of the search area poses a huge challenge," John Young, manager of Australian Maritime Safety Authority’s emergency response division, said. "A needle in a haystack remains a good analogy."
The Associated Press contributed to this report.