BEIJING — Malaysia on Tuesday released the full transcript of radio communications between the pilots on Flight 370 and air traffic controllers but reiterated that there was no indication of anything abnormal before the plane vanished last month.
The government said international investigators and Malaysian authorities still think the plane was deliberately flown off-course in the early hours of March 8 with 239 people on board.
But the possibility that the mystery of the missing Malaysia Airlines plane will never be unraveled appears to be growing, as the search in the southern reaches of the Indian Ocean continues to come up blank.
At a news conference in the western Australian city of Perth, the Australian appointed to head the search acknowledged the daunting nature of the task, as planes scour vast stretches of sea without many clues and the batteries on the location beacon built into the plane’s black box gradually run down.
Angus Houston, a former Australian defense minister, described the search as the most challenging he had ever seen.
The starting point for any search, he said, is usually the last known position of a plane or vehicle. “In this particular case, the last known position was a long, long way from where the aircraft appears to have gone,” he said, according to news agencies. “It’s very complex; it’s very demanding.”
On Tuesday, 10 planes and nine ships searched about 46,000 square miles of ocean west of Perth, in a hunt that keeps shifting based on new calculations about the plane’s likely path, satellite evidence and ocean currents. Australian officials said Tuesday that the weather in the search area was “marginal” as ships battled “heavy seas and strong winds.”
The search crews finished the day without finding evidence of the plane.
“What we really need to find now is debris, wreckage from the aircraft,” Houston said. “This could drag on for a long time.”
In Kuala Lumpur, Malaysian Defense Minister Hishammuddin Hussein released the transcript of the pilots’ last communications with air traffic control, with a new version of the last communication from the cockpit. The transcript showed one of the pilots signing off by saying, “Good night Malaysian three seven zero,” at one hour, 19 minutes and 29 seconds into the flight — not “All right, good night,” as the government had previously said.
The transcript reinforces the impression that everything in the cockpit was normal until that point.
Yet, a little later at 1:21 a.m., just as the plane was due to enter Vietnamese airspace, the aircraft’s transponder ceased transmitting its location. Soon afterward, the plane made an unscheduled sharp left turn, away from its planned flight path to Beijing and back toward the Malay Peninsula.
Malaysia Airlines had previously said it thought the plane’s 27-year-old co-pilot, Fariq Abdul Hamid, had uttered the final words. But Hishammuddin said police were still working to confirm that. “Forensic examination of the original recording is ongoing,” he said in a statement.
“The international investigations team and the Malaysian authorities remain of the opinion that, up until the point at which it met military primary radar coverage, MH370’s movements were consistent with deliberate action by someone on the plane,” he said.
Malaysian Prime Minister Najib Razak will travel to Perth on Wednesday to see the operations first hand and thank those taking part in the search. His Australian counterpart, Tony Abbott, said Monday that he was not putting any time limit on the search, and he vowed to solve the mystery “if this mystery is solvable.”
Nevertheless, Mick Kinley, a search official in Perth, said satellite imagery of the new search area had not given “anything better than low confidence of finding anything,” the Associated Press reported.
Houston, the former Australian defense minister, said the search would continue based on the imperfect information that the Joint Agency Coordination Center had at its disposal.
“But, inevitably, if we don’t find any wreckage on the surface, we are eventually going to have to, probably in consultation with everybody who has a stake in this, review what to do next,” he said.
The batteries in the black box are expected to expire about 30 days after the plane went down. Once those batteries die, without a much clearer indication of where the plane might have crashed it will be next to impossible to find the wreckage in the deep vastness of the Indian Ocean, experts say.