PEARCE AIR FORCE BASE, Australia — After 17 days of mystery over the fate of the missing Malaysia Airlines jet, Malaysia’s prime minister said Monday that a new analysis of satellite data had confirmed that the plane went down in the southern Indian Ocean with all its passengers and crew.
The announcement, which unleashed an outpouring of sorrow and grief among the families of the 239 people on board, narrowed the search area to deep waters west of Australia, but left many questions unanswered about why the plane flew to such a remote part of the world.
Officials in Australia on Tuesday signaled that those answers are not going to be coming soon, given the massive nature of the search, the remote area of where the plane likely crashed, and harsh weather.
Planes and ships had been crisscrossing about 1,500 miles southwest of Australia, but the search was called off early Tuesday because of 12-foot waves and heavy rain.
Analysts 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 headed only south, Prime Minister Najib Razak said Monday.
Najib said the new analysis of the flight path 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.
The aircraft’s last known position, according to the analysis, “is a remote location, far from any possible landing sites,” 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.”
Shortly before the prime minister spoke, Malaysia Airlines officials informed relatives of the missing passengers and crew.
Most were told in person or by telephone, the airline said, and some were sent a text message: “Malaysia Airlines deeply regrets that we have to assume beyond any reasonable doubt that MH370 has been lost and that none of those on board survived. As you will hear in the next hour from Malaysia’s Prime Minister, we must now accept all evidence suggests the plane went down in the Southern Indian Ocean.”
The Boeing 777, with 227 passengers and 12 crew members on board, was headed from Kuala Lumpur to Beijing when it disappeared on March 8.
The families of the passengers, two-thirds of whom are Chinese, had grown increasingly angry about the lack of clear information about the plane’s fate.
In a statement later in the day, the airline said that the families “have been at the heart of every action the company has taken since the flight disappeared,” and that when it “receives approval from the investigating authorities, arrangements will be made to bring the families to the recovery area.”
The Chinese Ministry of Foreign Affairs issued a statement demanding to see the analysis that led to Najib’s announcement.
“We have already asked that the Malaysian side go further in providing all the information and evidence used to reach this conclusion,” said the statement from Hong Lei, a spokesman for the ministry.
Chinese relatives of the missing marched Tuesday to the Malaysia Embassy, where they tried to rush the gates and chanted, “Liars!’’
The hunt for the missing plane has focused on a section of the southern Indian Ocean in recent days; an Australian naval vessel searched there Monday after a military surveillance aircraft spotted what was described as possible wreckage from the missing jetliner.
Finding the plane’s flight recorders, or black boxes, will be crucial to determining what may have caused its 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 US Navy has sent an unmanned underwater vehicle to Perth that could be used if debris is located, the Associated Press reported, citing Rear Admiral John Kirby, a Pentagon spokesman.
The Bluefin-21, expected to arrive in Perth on Wednesday, has side-scanning sonar and what is called a ‘‘multibeam echo sounder’’ that can be used to take a closer look at objects under water, he added. It can operate at a depth of 14,700 feet.
The waters off western Australia pose formidable challenges for the hunt for wreckage and the plane’s black boxes. After a number of false sightings during 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,” Abbott said.
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 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.
Chris McLaughlin, a vice president at Inmarsat, the British satellite operator, said the company had spent the past six days reviewing data about Flight 370 in close consultation with Boeing and others involved in the investigation and came to the conclusion that the plane must have flown to the south.
“Our measured series of signals very much mirror the predicted southern track after the last possible turn,” McLaughlin said, adding that they were consistent with previous indications that the plane continued on at more or less the same speed and in the same direct-ion 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 it submitted its findings Sunday to the Malaysians by way of the British safety agency, the Air Accidents Investigation Branch.
“What we still can’t say is what happened at the end, when the plane ran out of fuel,” McLaughlin said. “We have no way of knowing if it dropped from the sky or glided.”
A 777 jet can fly for hours on autopilot, according to experts.
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 many different directions.
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 Malaysian government has offered few 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.