KUALA LUMPUR, Malaysia -- The search for the missing Malaysian jet pushed deep into the northern and southern hemispheres Monday as Australia scoured the southern Indian Ocean and Kazakhstan -- more than 6,000 miles to the northwest -- answered Malaysia's call for help in the unprecedented hunt.

French investigators arriving in Kuala Lumpur to lend expertise from the two-year search for an Air France jet that crashed into the Atlantic Ocean in 2009 said they were able to rely on distress signals. But that vital tool is missing in the Malaysia Airlines mystery because flight 370's communications were deliberately severed ahead of its disappearance more than a week ago, investigators say.

Malaysia’s acting Transport Minister Hishamuddin Hussein shows maps of northern search corridor during a press conference at a hotel near the Kuala
Malaysia's acting Transport Minister Hishamuddin Hussein shows maps of northern search corridor during a press conference at a hotel near the Kuala Lumpur International Airport in Sepang, Malaysia, on March 17, 2014. (Vincent Thian/AP)

"It's very different from the Air France case. The Malaysian situation is much more difficult," said Jean Paul Troadec, a special adviser to France's aviation accident investigation bureau.

Malaysian authorities say the jet carrying 239 people was intentionally diverted from its flight path during an overnight flight from Kuala Lumpur to Beijing on March 8. Suspicion has fallen on the pilots because of their aviation experience, although Malaysian officials have said they are seeking background checks on everyone aboard the flight.


Advertisement

Malaysian police confiscated a flight simulator from the pilot's home on Saturday and also visited the home of the co-pilot in what Malaysian police Chief Khalid Abu Bakar initially said was the first police visits to those homes. The government, however, issued a statement Monday contradicting that account by saying police first visited the pilots' homes as early as March 9, the day after the flight.

Investigators haven't ruled out hijacking, sabotage, pilot suicide or mass murder, and they are checking the backgrounds of all 227 passengers and 12 crew members, as well as the ground crew, to see if links to terrorists, personal problems or psychological issues could be factors.

Malaysian Defense Minister Hishammuddin Hussein said at a news conference Monday that finding the plane was still the main focus, and he did not rule out finding it intact.

"The fact that there was no distress signal, no ransom notes, no parties claiming responsibility, there is always hope," Hishammuddin said.

Malaysia Airlines CEO Ahmad Jauhari Yahya said an initial investigation indicated that the co-pilot, Fariq Abdul Hamid, spoke the fight's last words -- "All right, good night" -- to ground controllers.

Malaysian officials previously have said those words came after one of the jetliner's data communications systems -- the Aircraft Communications Addressing and Reporting System -- already had been switched off, sharpening suspicion that one or both of the pilots may have been involved in the plane's disappearance.

Ahmad said Monday, however, 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. That opened the possibility that ACARS and the plane's transponders -- which make the plane visible to civilian air traffic controllers -- were severed later and at about the same time.

A Malaysia Airline Boeing 737-800 plane taxis by main terminal at Kuala Lumpur International Airport in Sepang on March 16, 2014. Malaysia.
A Malaysia Airline Boeing 737-800 plane taxis by main terminal at Kuala Lumpur International Airport in Sepang on March 16, 2014. Malaysia. (Vincent Thian/AP)

Malaysia's government in the meantime sent out diplomatic cables to all countries in the search area, seeking their help in providing planes and ships for the search, as well as to ask for any radar data that might help narrow the task.

Some 26 countries are involved in the search, which initially focused on seas on either side of Peninsular Malaysia, in the South China Sea and the Strait of Malacca.

Over the weekend, however, Malaysian Prime Minister Najib Razak announced that investigators determined that a satellite picked up a faint signal from the aircraft about 7½ hours after takeoff. The signal indicated that the plane would have been somewhere on a vast arc stretching from Kazakhstan down to the southern reaches of the Indian Ocean.

Hishammuddin said Monday that searches in the northern and southern stretches of the arc had begun, with countries from Australia up north to China and west to Kazakhstan joining the hunt.

Had the plane gone northwest to Central Asia, it would have crossed over countries with busy airspace, and some experts believe the person in control of the aircraft more likely would have chosen to go south. Authorities are not ruling out the northern corridor, however, and are eager for radar data that might confirm or rule out that path.

The northern search corridor crosses through countries including China, India and Pakistan -- all of which have indicated they have seen no sign of the plane.

An official with the Chinese civil aviation authority said the missing plane did not enter Chinese airspace, but the Chinese Defense Ministry and Foreign Ministry didn't immediately respond to questions on radar information.

Indonesian officials, based on radar data, have said the plane did not cross their territory. Air force spokesman Rear Marshall Hadi Tjahjanto said Monday that his country's search efforts were focusing on waters west of Sumatra in the Indian Ocean.

Australian Prime Minister Tony Abbott told Parliament that he agreed to take the lead in scouring the southern Indian Ocean for the aircraft during a conversation Monday with Malaysia's leader.

"Australia will do its duty in this matter," Abbott told Parliament. "We will do our duty to the families of the 239 people on that aircraft who are still absolutely devastated by their absence, and who are still profoundly, profoundly saddened by this as yet unfathomed mystery."

Two Australian Orion maritime planes that have been searching for the past week headed Monday to the southern Indian Ocean, with two more to join them in the coming 24 hours, Abbott said. New Zealand and U.S. planes also will join that team.

The southern Indian Ocean is the world's third-deepest and one of the most remote stretches of water in the world, with little radar coverage.