Lion Air Crash Investigators Probe Faulty Airspeed Readings

 - November 6, 2018, 9:06 AM

Readouts of the flight data recorder (FDR) recovered from the sunken wreckage of Lion Air Flight JT 610 show evidence that that the Boeing 737 Max 8 experienced faulty airspeed readings during its last four flights, but investigators have yet to determine any connection between the instrument anomalies and the October 29 crash that killed all 189 onboard. Indonesia's National Transportation Safety Committee (KNKT) chairman Soerjanto Tjahjono revealed the development during a press conference on November 5.

The FDR contained more than 1,790 parameters spanning 19 flights over some 69 hours. Despite incurring heavy damage due to the force of impact, the FDR’s data recording module remained operable, allowing investigators to confirm the airspeed indicator had indeed malfunctioned on four separate flights. While the KNKT has yet to conclude any connection between the faulty instrument and the crash, investigators continue to work with the U.S. National Transportation Safety Board (NTSB) and Boeing to conduct a detailed inspection of the airspeed indicator.  

The KNKT’s sub-committee head for air accidents, Nurcahyo Utomo, said investigators now are trying to determine whether the malfunction stems from the indicator’s computer system, device, or sensor. Investigators have begun reviewing maintenance logs and questioning pilots and technicians about the aircraft’s three previous flights.

Revelations of a faulty airspeed indicator come days after authorities revealed ADS-B data from the airliner’s October 28 evening flight indicated erratic variations in altitude and airspeed. On October 31, Indonesian transport minister Budi Karya Sumad ordered the temporary suspension of Lion Air technical director Muhammad Asif along with a number of technicians who cleared JT 610 for operation. The transport ministry, which has appointed Muhammad Rusli as acting technical director, continues intensive ramp inspections on 40 percent of Lion’s in-service fleet. 

Search-and-rescue teams have yet to recover the cockpit voice recorder (CVR), believed embedded in the muddy seabed, northeast of Jakarta, where the 737 Max 8 crashed 13 minutes into its flight. On November 5, navy divers recovered the emergency locator transmitter from a depth of 98 feet. Searchers have also retrieved parts of the airplane’s landing gear and fuselage from the Java Sea.

Meanwhile, dangerous sea currents continue to hamper recovery of the wreckage and the victims. In a tragic turn of events, an experienced Indonesian diver died on November 2 during search-and-rescue efforts.  

As the search continues, Lion Air has pledged nearly $90,000 in compensation to each of the victims’ families and $100,000 to the families of JT 610’s eight aircraft crew.