CANBERRA, Australia — Shortly after the missing Malaysian airliner disappeared from radar, airline officials on the ground tried repeatedly to call the crew of the Boeing 777 using a satellite phone that might have left clues to the jet's flight path.
Now an analysis of those failed attempts to reach Flight 370 could alter the search for the plane.
Australian Transport Safety Bureau Chief Commissioner Martin Dolan said Thursday that the sprawling search area in the southern Indian Ocean may be extended farther south based on the new analysis, which suggests that the aircraft turned that direction earlier than previously believed.
Investigators have long been aware of the calls but only recently developed methods to analyze the phone data for hints about the plane's final hours. It was through a similar analysis of satellite data from the plane's jet engine transmitters that investigators were able to define the current search area.
The jetliner disappeared March 8 after veering off its northerly course from Kuala Lumpur to Beijing and has become one of aviation's biggest mysteries. It is thought to have crashed 1,800 kilometers (1,100 miles) off Australia's west coast, but no trace of the aircraft or the 239 people aboard has been found.
Dolan, the chief crash investigator, said he would meet with international experts next week to decide whether the 60,000-square kilometer (23,000-square mile) targeted search area should be extended or shifted south.
Malaysia Airlines ground staff tried twice to call the crew. The new analysis applies to satellite data from the first call.
By the time the calls were attempted, the plane had become invisible to civilian radar and gone silent. It flew west past Sumatra and beyond the range of Malaysian military radar.
The analysis suggested the jet was already flying south when the first phone call was attempted, less than 20 minutes after the plane dropped off military radar.
"We're now more confident that it turned comparatively early. That does make a difference to how we prioritize the search along the seventh arc," Dolan added, referring to the broad area where investigators believe the flight ran out of fuel and crashed, based on the last ping from the engine transmitters.
With the hunt for the airliner set to resume in a few weeks, investigators are attempting to calculate which parts of the search area should be examined first.
The analysis adds weight to a crash-investigation report issued in June by the Australian Transport Safety Bureau in which most modeling of the plane's potential flight paths factored in a relatively early turn to a southerly course.
The current search area covers a swath of ocean 700 kilometers (435 miles) long and 80 kilometers (50 miles) wide. An initial search of 850 square kilometers (330 square miles) of seabed to the north ended with officials concluding that they were focusing their efforts in the wrong place.
Also Thursday, Australian Deputy Prime Minister Warren Truss and Malaysian Transport Minister Liow Tiong Lai signed an agreement in Canberra for the two countries to share the ongoing costs as the search progresses to the expensive next phase, which could take up to a year and cost 52 million Australian dollars ($48 million).
Until now, each country involved in the search has borne its own costs.
In three weeks, a Dutch contractor will begin the operation with three vessels towing underwater vehicles equipped with side-scan sonar, multi-beam echo sounders and video equipment, Truss said.
"We need to find the plane. We need to find the black box in the plane so that we can have a conclusion in the investigation," Liow said.
Malaysia, as the country where the jet was flagged, has overall responsibility for the crash investigation. But Australia is responsible for search-and-rescue operations.
Chinese Vice Minister of Transport He Jianzhong, who also attended the Canberra meeting, said the ministers agreed that the search will not be interrupted or given up. Most of the passengers — 153 — were Chinese.