PEARCE AIR FORCE BASE, Australia — Malaysia’s prime minister said Monday that further analysis of satellite data confirmed that the missing Malaysian airliner went down in the southern Indian Ocean. The announcement narrowed the search area but left many questions unanswered about why it flew to such a remote part of the world.
Experts had previously held out the possibility that the jet could have flown north instead, toward Central Asia, but the new data showed that it could have gone only south, said the prime minister, Najib Razak.
Mr. Najib appeared eager to bring closure to the families of the passengers on Malaysia Airlines Flight 370, two-thirds of whom are Chinese. The families have grown increasingly angry about the lack of clear information about the plane’s fate. The Boeing 777, with 227 passengers and 12 crew members onboard, was headed from Kuala Lumpur to Beijing when it disappeared on March 8.
The aircraft’s last known position, according to the analysis, “is a remote location, far from any possible landing sites,” Mr. Najib said. “It is therefore with deep sadness and regret that I must inform you that, according to this new data, Flight MH370 ended in the southern Indian Ocean.
The new analysis of the flight path, the prime minister said, came from Inmarsat, the British company that provided the satellite data, and from Britain’s air safety agency. The company had “used a type of analysis never before used in an investigation of this sort,” he said.
Shortly before the prime minister spoke at 10 p.m. local time, Malaysia Airlines officials informed the relatives of the missing passengers and crew gathered at a hotel near Kuala Lumpur, and sent text messages to those who were elsewhere.
The hunt for the missing plane has focused on a section of the southern Indian Ocean in recent days, and an Australian naval vessel searched there on Monday after a military surveillance aircraft spotted what was described as possible debris from the missing jetliner.
Mr. Najib said the Malaysian authorities would hold a news conference on Tuesday to give further details about the satellite data analysis and other developments in the search.
After a number of false sightings over more than two weeks of search efforts, Australian officials were cautious about what the crew members of a Royal Australian Air Force P-3 Orion aircraft had spotted as they combed the search area Monday.
Prime Minister Tony Abbott told Parliament that the crew reported seeing two objects, “a gray or green circular object” and “an orange rectangular object,” in the ocean about 1,550 miles southwest of Perth, in western Australia.
“We don’t know whether any of these objects are from MH370,” Mr. Abbott said. The objects in the water could be flotsam, he said.
Even so, the tenuous lead was treated in Australia as a significant development.
The Australian Maritime Safety Authority said that a naval survey ship, the Success, was on the scene and that the crew was looking for the objects. Andrew Thomas, a journalist with the Al Jazeera television news network who was aboard the Orion aircraft, said that the crew spotted four confirmed objects, that flares were dropped and that the Success was nearby.
The floating objects spotted by the Australian plane were different from the possible debris reportedly seen during the first search flights by two Chinese Air Force Ilyushin IL-76 aircraft the same day. Later on Monday, Australian authorities said all search aircraft had finished their missions for the day and had reported no further sightings.
The crew of one of the Chinese planes spotted “suspicious objects,” according to Xinhua, the official Chinese news agency, which had a reporter on the search plane. But the description was vague and the observation was made during poor weather conditions. A Chinese diplomat in Australia, Qu Boxun, told reporters that the plane was at “a very high altitude when the objects were spotted.”
Chris McLaughlin, a vice president at Inmarsat, the British satellite operator, said the company had spent the past six days reviewing the data it had abot Flight 370 in close consultation with Boeing and other parties involved in the investigation. Earlier analysis of the seven signals received on March 8 by one of its satellites over the Indian Ocean told investigators that the plane had probably wound up somewhere along of two broad arcs, one stretching south into the ocean and the other stretching north from Laos through southwestern China into Central Asia. But the new analysis announced on Monday allowed investigators to rule out the northern arc.
“Our measured series of signals very much mirror the predicted southern track after the last possible turn,” Mr. McLaughlin said, adding that they were consistent with previous indications that the plane continued on at a more or less constant speed and direction for the last hours of the flight.
He said that Inmarsat was confident enough in the new analysis, which it reviewed with Boeing and with a number of independent aviation experts, that the company submitted its findings on Sunday to the Malaysians by way of the British safety agency, the Air Accidents Investigations Bureau.
“What we still can’t say is what happened at the end, when the plane ran out of fuel,” Mr. McLaughlin said. “We have no way of knowing if it dropped from the sky or glided.”
Inmarsat has provided investigators with its estimate of the plane’s coordinates when it emitted the last of the signals, at 8:11 a.m. Malaysian time on March 8. “We are very comfortable with the guidance we have been giving,” he said.
The search for the aircraft’s fuselage and other bulky parts of the jet that probably sank to the bottom of the ocean is likely to be focused within a limited distance from the suspected flight path. But the search for floating debris, which investigators say will offer proof that the jet hit the water, is likely to be increasingly widespread.
Erik van Sebille, an oceanographer at the University of New South Wales who studies and has conducted experiments on the flow of water around Australia, said currents in the southern Indian ocean could scatter floating debris in very different directions.
“The whole ocean down there is like a pinball machine,” Dr. van Sebille said. “It is difficult to track or predict where water goes, or do what is really important now, which is to backtrack where water came from.”
Dr. van Sebille described the conditions of the southern Indian Ocean as “extremely hostile,” with large waves, swirling currents and winds that are among the strongest on the planet.
“The longer it takes, the harder it will be to backtrack those pieces of debris,” he said.
Finding the plane’s flight recorders, or black boxes, will be crucial to determining what may have caused the plane’s disappearance. The devices are designed to transmit signals to help searchers locate them, but searchers have only about two weeks left to find them before the devices’ batteries run out.
The United States Pacific Command said on Monday that it would move a Towed Pinger Locator System, capable of locating a black box to a depth of 20,000 feet, into the region. “This movement is simply a prudent effort to pre-position equipment and trained personnel closer to the search area, so that if debris is found, we will be able to respond as quickly as possible, since the battery life of the black box’s pinger is limited,”Cmdr. Chris Budde, a Seventh Fleet operations officer, said in an email statement.
The Malaysian government has been less vocal lately about any findings from the police inquiry into the people on the missing plane, including the captain, Zaharie Ahmad Shah, and the junior pilot in the cockpit, Fariq Abdul Hamid. Investigators and officials have said that the plane’s extraordinary trajectory, veering far off course just after its last radio contact with the ground, and the fact that its transponders stopped working at about the same time appeared to involve actions by someone experienced in aviation.
Hishammuddin Hussein, the Malaysian defense minister and acting transportation minister, said on Monday that the police had interviewed more than a hundred people, including relatives of each pilot. He said a committee was considering whether to make public the transcript of the pilots’ communications with air controllers before the plane disappeared.
Mr. Hishammuddin also confirmed that the plane was carrying wooden shipping pallets. One of the objects reportedly sighted in the Indian Ocean was such a pallet, but they are very commonly used and one in the ocean could have come from a ship.
The chief executive of Malaysia Airlines, Ahmad Jauhari Yahya, said on Monday that that the plane was also carrying about 440 pounds of lithium batteries, which can be a fire hazard n certain circumstances. But he said the batteries had been handled and packaged so that they were were deemed “non-hazardous” under civil aviation standards. The cargo also included some fruit and radio equipment, he added.
Mr. Ahmad Jauhari did not directly answer a question about whether the full cargo manifest had been given to Australian investigators, saying that was a matter for the investigation team. “If the Australians request this, they have to go and request it from the investigating team,” he said.
Separately on Monday, a Malaysia Airlines Airbus A330-300 that was headed overnight to Seoul, South Korea, from Kuala Lumpur was diverted to Hong Kong because of a generator failure, the airline announced. The carrier said that an auxiliary generator continued to supply power to Flight 66, which was carrying 271 passengers. A spokeswoman for the Hong Kong airport authority said the flight had landed without incident shortly before 3 a.m.
Mohd Taufik Atman, a spokesman for the airline, said the plane was under repair and would resume service once a technical crew gave the go-ahead. He said that the airline had no plans to investigate the incident further. “This was a mechanical issue,” he said.