When Sriwijaya Air’s 26-year-old Boeing Co 737-500 aircraft reached 8,150 toes (2,484 meters) after take-off, the left engine throttle lever moved again whereas the correct lever stayed in its unique place, in accordance with Indonesia’s Nationwide Transportation Security Committee (KNKT).
“We do not know if it is damaged or not, nevertheless it’s an anomaly as a result of the left moved far again, the correct didn’t as if it was caught,” KNKT investigator Nurcayho Utomo informed reporters.
At about 10,900 toes, the autopilot disengaged and the aircraft rolled to the left greater than 45 levels and began its dive, in accordance with the report.
Beginning with only one aircraft in 2003, Sriwijaya has change into the nation’s Quantity 3 airline group, aided by its technique of buying previous planes at low-cost costs and serving routes uncared for by opponents.
There had been two prior issues reported with the autothrottle system, which mechanically controls engine energy primarily based on upkeep logs. However the challenge was rectified on January 5, 4 days earlier than the crash, KNKT stated.
A working autothrottle isn’t required for a aircraft to be dispatched as pilots can management the thrust levers manually with their fingers.
Divers are nonetheless trying to find the aircraft’s cockpit voice recorder, which may assist investigators perceive the actions taken by the pilots, each of whom have been skilled with 17,900 hours for the captain and 5,100 hours for the primary officer.
The report highlighted the significance of upset restoration coaching for pilots and the popularity of repetitive aircraft defects, simply over six years after an AirAsia Indonesia crash the place these have been among the many points raised.
KNKT stated that Sriwijaya had taken security actions after the crash, together with including upset restoration coaching in its subsequent pilot proficiency verify and reminding engineers that repetitive defects should be dealt with in accordance with security manuals.
The airline despatched a memo to pilots reminding them to put in writing detailed stories to assist engineers troubleshoot issues.
The Directorate Common of Civil Aviation additionally mentioned the dealing with of repetitive issues and upset prevention and restoration coaching with different Indonesian operators after the crash, KNKT stated.
Boeing stated it might proceed to help the investigation.
The preliminary report, as is normal, laid out factual data obtained so far however didn’t listing the contributing components to the crash. That may require additional investigation.
Security specialists say most air accidents are brought on by a mix of things that may take months to ascertain. Below worldwide requirements, the ultimate report is due inside a 12 months of the crash.