BANGKOK: The weather over the Indonesian capital, Jakarta, was sunny with little wind. The plane was a pristine Boeing that had taken to the skies only in August.
But shortly after 6.30am on Monday morning, after a jagged takeoff full of unexplained descents, Lion Air Flight 610 plunged into the Java Sea with 189 people on board. No survivors have been found.
The exact sequence of events that led to yet another aviation disaster in Indonesia is still unclear, and may only emerge once flight-data recorders are recovered from the waters northeast of Jakarta.
Experts are looking to see if an underlying problem, either mechanical or human or both, may have caused it.
“This doesn’t seem like a more normal crash caused by something like weather or an old plane,” said Gerry Soejatman, an Indonesian aviation expert. “That’s what makes us worry.”
One theory is that the pilots received inaccurate altitude or speed readings from probes affixed to the outside of the airplane, part of a sensitive set of instruments called the pitot-static system.
Problems with these instruments are thought to have contributed to other crashes. And they may have been the issue the night before the crash, when the same Lion Air plane experienced problems flying to Jakarta from the resort island of Bali.
On Tuesday afternoon, Indonesian transportation officials acknowledged that they had not spoken to ground crews about the plane and the problems it experienced after it left Bali.
It is also possible, experts said, that the type of plane involved in the crash – the Boeing 737 Max 8, which entered commercial service only around a year and a half ago – may have another flaw that had not manifested itself in other fleets before because it is so new.
On Tuesday, Ony Soerjo Wibowo, an air safety investigator for the Indonesian Transportation Safety Committee, said the immediate priority was finding the so-called black boxes – the flight data recorder and cockpit voice recorder – which may offer critical information about what happened in the final minutes of the flight.
The crash of Flight 610 occurred minutes after the plane took off from Jakarta, bound for the small city of Pangkal Pinang off the island of Sumatra.