0127 GMT January 18, 2019
National Transportation Safety Committee chairman Soerjanto Tjahjono said the problem was similar on each of the four flights, including the fatal flight on Oct. 29 in which the plane plunged into the Java Sea minutes after taking off from Jakarta, killing all 189 people on board, AP reported.
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.”
Indonesian investigators, the plane’s manufacturer, Boeing, and the US National Transportation Safety Board are formulating a more specific inspection for Boeing 737 MAX 8 planes related to the airspeed problem, Tjahjono said.
Lion Air has said a technical problem with the jet was fixed after problems with the Bali to Jakarta flight.
Investigator Nurcahyo Utomo said investigators need to review maintenance records, including what problems were reported, what repairs were done including whether components were replaced, and how the repairs were tested before the 2-month-old plane was declared airworthy.
“Currently we are looking for the cause of problem,” he said “Whether the trouble came from its indicator, its measuring device or sensor, or a problem with its computer. This is what we do not know yet and we will find it out,” he said.
At the meeting with family members, Tjahjono had said that information downloaded from the jet’s flight data recorder was consistent with reports that the plane’s speed and altitude were erratic after takeoff on its final flight. Searchers are still trying to locate the cockpit voice recorder.
Many families face an agonizing wait for missing relatives to be identified. Police medical experts have received nearly 140 body bags of human remains and have identified 14 victims.
Relatives questioned why the plane had been cleared to fly after suffering problems on its Bali to Jakarta flight on Oct. 28 that included a rapid descent after takeoff that terrified passengers.
Tjahjono said the large amount of small debris and the relatively small area the debris was found in showed the plane hit the water at a very high speed.
“The plane was intact when it plunged to the sea, it did not explode in the air, and the aircraft engine was running when it touched the water at high RPM — it’s marked by the loss of all blades of the turbine,” he said.
The Lion Air crash is the worst airline disaster in Indonesia since 1997, when 234 people died on a Garuda flight near Medan.