The off-duty pilot, who was seated in the cockpit jumpseat, correctly identified the problem the Lion Air crew faced and explained to them how to disable a malfunctioning flight-control system and save the plane, Bloomberg reported, citing two people familiar with Indonesia's investigation.
According to the report, the next day, when the Lion Air Boeing plane crashed into Indonesia's Java Sea under the command of a different crew, the pilots faced an identical flight control system malfunction.
"All the data and information that we have on the flight and the aircraft have been submitted to the Indonesian NTSC. We can't provide additional comment at this stage due to the ongoing investigation of the accident," Lion Air spokesman Danang Prihantoro said by phone, Bloomberg reported.
Lion Air, Indonesia's largest airline, has a notoriously bad safety record. Government investigators have accused the company of ignoring their commands to ground planes with proven problems. In October 2018, a Boeing 737 MAX 8 operated by Indonesia's Lion Air plunged into the Java Sea soon after take-off, killing all 189 passengers and crew on board. The plane had experienced days of incorrect data readings, according to Indonesian officials. In fact, before the penultimate flight, engineers had replaced one of the angle-of-attack sensors.
On March 10 another Boeing 737 MAX 8 belonging to the Ethiopian Airlines crashed killing all 157 people from 35 countries who were on board. The causes of the accident are yet to be determined.
In the wake of tragedies, aviation authorities and airlines around the world have either grounded their 737 MAX 8 series aircraft or closed their airspace to them.