The night sky was clear above the clouds, and the last glimmer of a setting half-moon had faded when Malaysia Airlines Flight 370, cruising at 35,000 feet over the Gulf of Thailand, approached the border between Malaysian and Vietnamese airspace on its usual route to Beijing. What happened next should have been routine for a twice-daily milk run between two of Asia’s most important cities.
Instead, in those early hours of March 8, pilots flying nearby heard an unusual crescendo of chatter on the radio frequencies used by radar control in Vietnam and Malaysia. Air traffic personnel in both countries were trying and failing to reach the plane.
On Saturday, authorities said a Chinese satellite had made a new sighting of a possible object floating in the southern Indian Ocean in the area that is now the focus of the search, and China was sending ships to investigate.
This report presents a portrait of Flight 370 and the effort to resolve what has become perhaps the most perplexing case in modern aviation – one that investigators say may take years to solve, or could remain a mystery forever.
Boarding began about midnight. Among the passengers were two men using stolen passports: Pouria Nourmohammadi Mehrdad, 19, and Seyed Mohammed Reza Delavar, 29 – Iranian men described by Interpol as migrants being smuggled into Europe.
By the time it pulled up to the gate at Kuala Lumpur International Airport on March 8, the plane had completed more than 7,500 flights and clocked more than 53,400 hours in the air, according to Flightglobal, a news and data service for the aviation sector. That put it well within the average economic life of 23 years for a wide-body passenger jet.
Outside, ground crews loaded the passenger luggage into the jet’s cargo hold. The airline said no hazardous or valuable goods were on the flight. But among the cargo were a “significant” number of lithium batteries – which can be flammable – more than is typically sent in a shipment, one U.S. official said.
In the cockpit were the pilots: the captain, Zaharie Ahmad Shah, 53, and his first officer, Fariq Abdul Hamid, 27.
After nudging away from the gate, the plane lifted off at 41 minutes after midnight.
At 1:07 a.m., as the jet approached the east coast of Peninsular Malaysia, ground crews received what the authorities have described as a routine text message from the Aircraft Communications Addressing and Reporting System, or ACARS, which sends regular updates on the condition of the plane by radio or satellite.
As the plane approached Vietnamese airspace, air traffic control in Subang, outside Kuala Lumpur, told the pilots that they were being transferred to radar control in Ho Chi Minh City. At 1:19 a.m., a voice identified by the authorities as that of the first officer, Fariq, replied, “All right, good night.”
According to the flight plan, the plane would have turned northeast toward Beijing. Instead, not quite two minutes after the voice contact, Flight 370’s transponder stopped responding. It is unclear whether someone turned a dial on a panel between the pilot and first officer and put the transponder in standby mode, or whether a malfunction caused it to go quiet. But one moment, radar scopes showed the plane traveling northwest at 471 knots (542 mph). The next moment, it was gone.
The military in Vietnam marked the time at 43 seconds past 1:20 a.m.
As air traffic controllers struggled to re-establish contact with Flight 370, military radar at the Butterworth air force base on Malaysia’s west coast picked up an unidentified aircraft near where the plane disappeared.
But the watch team, normally an officer and three enlisted personnel, either failed to notice the signal or decided not to designate and track it as a “zombie,” which would have pushed the information up the chain of command, possibly alerting air command.
At a briefing on the base the next night, about 80 air force personnel were told there was “no proof” the unidentified signal showed the missing plane making a sharp turn, flying back across Peninsular Malaysia and then turning again and heading northwest over the Strait of Malacca, a person familiar with the situation said.
But investigators now believe that is exactly what happened.
The failure to recognize Flight 370 in the radar data – or refusal to do so, to avoid the embarrassment of admitting an unidentified plane had breached air defense – meant the Malaysian authorities continued to search in the seas to the east instead of the west of the peninsula. Military radar last recorded the signal at 2:22 a.m., about 200 nautical miles northwest of Butterworth, according to an image of the radar track.
The authorities also failed to move quickly on data that showed the plane continuing to fly nearly seven more hours: a series of regular handshake signals from the plane to a satellite seeking to determine if the aircraft was still in range.
Chris McLaughlin, a vice president at Inmarsat, the satellite communications firm, said technicians pulled the logs of all transmissions from the plane within four hours of its disappearance. Then, after a day without sign of the plane, they began scouring the company’s databases for any trace of Flight 370.
“We decided to go have another look at our network to see if there was any data that we had missed,” McLaughlin said. It turned out there was. Inmarsat technicians identified what appeared to be a series of fleeting “pings” between Flight 370, a satellite over the Indian Ocean and a ground station in Perth, Australia.
The signals – seven of them transmitted at one-hour intervals – were an important clue. But while they carried a unique code identifying the aircraft as Flight 370, the signals contained no positioning or other data that could indicate where the plane was when it sent them.
The afternoon of March 9, a team of Inmarsat engineers set to work using the principles of trigonometry to determine the distance between the satellite and the plane at the time of each ping, and then to calculate two rough flight paths. The plane, they concluded, had turned again. But it may have then traveled in more or less a straight line, heading north over countries likely to have picked it up on radar, or south toward the Indian Ocean and Antarctica.
The Malaysian government said it received Inmarsat’s data on March 12 and spent three days analyzing and vetting it with U.S. investigators before redirecting the search March 15.
By then, more than a week had passed since the last satellite ping, recorded at 8:11 a.m. on March 8. It appears to have come from over the southern Indian Ocean, halfway around the world from where the plane should have been, on a tarmac in Beijing.