The pilots of the doomed Lion Air Boeing 737 MAX spent their final moments in a desperate search to understand why the jet was lurching downwards, but ran out of time before it hit the water, it has been revealed.
Investigators examining the Indonesian crash are considering how a computer ordered the plane to dive in response to data from a faulty sensor and whether the pilots had enough training to respond appropriately to the emergency, among other factors.
“They didn’t seem to know the trim was moving down,” a source told Reuters. “They thought only about airspeed and altitude. That was the only thing they talked about.”
It is the first time the voice recorder contents from the Lion Air flight have been made public. Three sources discussed them on condition of anonymity.
The news comes after it was also revealed that on the same aircraft’s penultimate flight a day earlier, an off-duty pilot who happened to be in the cockpit saved the plane from what appears to have been an identical issue.
According to a Bloomberg report, the extra pilot managed to diagnose the problem and disabled a malfunctioning flight-control system which averted disaster.
The investigation into the crash, which killed all 189 people on board in October, has taken on new relevance as the US Federal Aviation Administration (FAA) and other regulators grounded the model last week after a second deadly accident in Ethiopia.
Preliminary information from the flight data recorder of the Ethiopian Airlines plane that crashed a week ago and killed 157 people shows “clear similarities” with the Lion Air flight, Ethiopia’s transport minister said on Tuesday.
The pilots of the Lion Air flight remained calm for most of the flight, the sources said. Near the end, the captain asked the first officer to fly while he checked the manual for a solution.
About one minute before the plane disappeared from radar, the captain asked air traffic control to clear other traffic below 3,000 feet and requested an altitude of “five thou”, or 5,000 feet, which was approved, the preliminary report said.
As the 31-year-old captain tried in vain to find the right procedure in the handbook, the 41-year-old first officer was unable to control the plane, two of the sources said.
The flight data recorder shows the final control column inputs from the first officer were weaker than the ones made earlier by the captain.
“It is like a test where there are 100 questions and when the time is up you have only answered 75,” the third source said. “So you panic. It is a time-out condition.”