Indonesia's National Transportation Safety Committee said it had agreed with Boeing on procedures that the airplane manufacturer should distribute globally on how flight crews can deal with "angle of attack" sensor problems following the October 29 crash that killed all 189 people on board.
"We are formulating, with NTSB and Boeing, detailed inspections regarding the airspeed indicator", according to Soerjanto Tjahjono, head of the committee.
The operations-manual bulletin was issued Tuesday, Boeing said in a statement posted to Twitter, and tells flight crews to use existing guidelines when dealing with erroneous inputs from the so-called angle of attack sensor.
"This is a preventive measure ...(The accident) is a very expensive lesson for us".
Airspeed indicators have been around for decades to tell pilots how fast they are flying. "One belongs to the pilot in command and one belongs to the co-pilot". Under some circumstances, such as when pilots are flying manually, the MAX jets will automatically try to push down the nose if they detect that an aerodynamic stall is possible, a person familiar with the matter said.
A spokesman for Chicago-based Boeing couldn't immediately be reached for comment.
Alan Diehl, a pilot and safety consultant, said the report that the same problem happened four times and was never fixed suggests that the problem may have been intermittent, making it harder to pin down.
Authorities are yet to recover the jet's cockpit voice recorder from the sea floor, just northeast of Jakarta, where the plane crashed 13 minutes into its flight. He did not provide further details about the problem.
"We checked that spot, located around 50 meters from the location of finding the first black box".
Search and rescue agency head Muhammad Syaugi tearfully apologised on Monday as relatives' clamour for answers grew louder, with accusations that the pace of recovery is lagging.
The search effort has involved 151 divers, five helicopters, 61 ships, ranging from fishing boats to ships with advanced sonar scanners, as well as underwater drones.
"We are still focusing on handling the families of the victims, including returning their remains to their home", Sirait said by phone.
Representatives of 737 Max operators, Singapore Airlines offshoot SilkAir, Garuda Indonesia and Canada's WestJet, said they had not yet received a bulletin from Boeing, Reuters reports.
However, previous year Boeing had to briefly ground its 737 MAX fleet as discrepancies were found in its engines.
The glitch had been repeatedly serviced and Lion Air's technical team declared the plane to be airworthy. "People panicked. It dropped about 400 feet", said Gaharu, adding that he had confirmed the height of the drop on a flight-tracking website. Its transport safety panel investigated 137 serious aviation incidents from 2012 to 2017.
Relatives of those who perished in the Lion Air crash have returned to the site of the crash in the Java Sea to say their final goodbyes. Syahrul Anto, 48, was reported missing by his diving partner on Friday.