Faulty component, crew response led to AirAsia crash: Probe

Jakarta, December 1

Chronic problems with a faulty rudder system and the way pilots tried to respond were major factors in the crash of an Indonesian AirAsia jet last year that killed all 162 people on board, investigators said on Tuesday.

The Airbus A320 crashed into the Java Sea on December 28, less than halfway into a two-hour flight from Indonesia’s second-biggest city of Surabaya to Singapore.

In their first public report, Indonesian investigators did not pinpoint a single underlying reason why flight QZ8501 disappeared from the radar, but set out a sequence spotlighting the faulty component, maintenance lapses and crew actions.

“There was a chain of events, starting with a broken (part), how it was handled and then after it was handled what the consequences were and how the pilot handled it. It’s difficult for me to say what the main cause was,” National Transportation Safety Committee (NTSC) investigator Nurcahyo Utomo said. Bad weather did not play a role.

The NTSC said a system controlling rudder movement on the plane had cracked soldering that had malfunctioned repeatedly, including four times during the flight and 23 times over the previous year.

Officials told reporters there were indications from the black box data recorder that crew had tried to shut off power to the computer that controls the rudder system by resetting a circuit breaker, something not usually done during flight. They cautioned there was no proof of this but said they had recommended to Indonesia AirAsia and Airbus that they take steps to prevent pilots from “improvising” when faced with problems. “The thing we recommend is to please provide some procedure to prevent the pilots from improvising. Today maybe they improvise by pulling the circuit breaker, tomorrow they may do something else,” said Utomo.

Investigators confirmed that to reach the circuit breaker, the captain would have had to leave his seat. In February, the NTSC said there was no evidence for a Reuters report that the captain had left his seat or that the power was reset. Flown by the French co-pilot, the plane reared higher and entered a stall, a state in which the aircraft loses lift. — Reuters