A rudder control system problem that had occurred 23 times in the previous 12 months, coupled with the pilots' response, led to last year's crash of an AirAsia plane that killed all 162 people on board, Indonesian investigators said Tuesday. The National Transportation Safety Committee said an analysis of Flight 8501's data recorder showed the rudder control system had sent repeated warnings to the pilots during the Dec. 28 flight between the Indonesian city of Surabaya and Singapore. Aircraft maintenance records for the Airbus A320 showed that problems with the rudder system, caused by a cracked soldering joint on an electronic circuit board, had been reported 23 times during the year prior to the crash, with more frequent occurrences in the three months before the accident.
After the fourth warning during the flight, the pilots attempted to reset the control system while flying the plane manually, which caused it to enter a prolonged stall from which they were unable to recover, and the plane plowed into the Java Sea, the investigators said. The plane's voice recorder indicated possible confusion between the pilot and co-pilot, according to investigator Nurcahyo Utomo. At one point, the pilot said "pull down," but in fact the plane was ascending. "It seemed that there was a miscommunication between the pilot and co-pilot after the fourth fault," Utomo said. Bad weather conditions did not play a role, as initially believed, the investigators said. (A family of 10 missed the doomed flight by minutes after the departure time was changed.)