Indonesia's National Transportation Safety Committee (KNKT) said yesterday an airspeed indicator of a Boeing Co. 737 MAX plane that crashed last week killing all 189 people on board was damaged for its last four flights.

The damage was revealed after data had been downloaded from the plane's flight data recorder, KNKT chief Soerjanto Tjahjono told reporters, adding that it was asking Boeing and US authorities what action to take to prevent similar problems on this type of plane around the world.

"We are formulating, with NTSB and Boeing, detailed inspections regarding the airspeed indicator," he said, referring to the US National Transportation Safety Board.

It was not immediately clear whether the reported problem stemmed from a mechanical or maintenance issue, nor whether US authorities would order any checks.

"We don't know yet where the problem lies, what repair has been done, what their reference books are, what components have been removed," said Nurcahyo Utomo, the KNKT sub-committee head for air accidents.

“These are the things we are trying to find out: what was the damage and how it was fixed," he said.