The "black box" data recorder from a crashed Lion Air jet shows its airspeed indicator malfunctioned on its last four flights, investigators said Monday, just hours after distraught relatives of victims confronted the airline's co-founder at a meeting organised by officials. National Transportation Safety Committee chairman Soerjanto Tjahjono said the problem was similar on each of the four flights, including the fatal flight on October 29 in which the plane plunged into the Java Sea minutes after taking off from Jakarta, killing all 189 people on board.

Erratic speed and altitude on the plane's previous flight, from Denpasar on Bali to Jakarta, were widely reported and "when we opened the black box, yes indeed the technical problem was the airspeed or the speed of the plane," Tjahjono told a news conference. "Data from the black box showed that two flights before Denpasar-Jakarta also experienced the same problem," he said. "In the black box there were four flights that experienced problems with the airspeed indicator."