History of Flight
SriLankan Airlines Flight UL134, a scheduled service from Tiruchirappalli International Airport (TRZ), India, to Bandaranaike International Airport (BIA), Colombo, Sri Lanka, departed TRZ at 1045 hours UTC on 8 October 2014. Takeoff was from runway 09 under good visibility conditions. Shortly after departure, the flight crew declared a technical reason and returned to TRZ, landing without incident. Post-flight functional tests on the reported slat/flap retraction defect found the system operating normally. The flight later recommenced to BIA, landing at approximately 1340 hours UTC.
Investigation
The incident was initially reported via a Mandatory Occurrence Report (MOR) on 10 October 2014. The Civil Aviation Authority of Sri Lanka (CAASL) Airworthiness Inspector determined that functional checks were satisfactory. However, anonymous information suggesting concealment of facts prompted CAASL to appoint an Aircraft Accident Investigation Board (AAIB) under Section 56(1) of the Civil Aviation Act No 14 of 2010 to investigate possible willful violations.
Findings
The investigation identified several findings:
- The flight crew did not follow Standard Operating Procedures (SOPs) contained in the Flight Crew Operating Manual (FCOM) and Quick Reference Handbook (QRH) regarding the slat/flap abnormal configuration.
- The flight crew failed to accurately report the defect in the Technical Log and the MOR.
- The flight crew did not conduct a cabin crew briefing or make a public announcement to passengers about the emergency situation.
Probable Causes
The AAIB determined the probable causes of the incident as: 1. The flight crew failed to follow the SOPs in the FCOM and QRH regarding the slat/flap abnormal configuration. 2. The flight crew failed to accurately report the defect in the Technical Log and the MOR. 3. The flight crew did not initiate a cabin crew briefing or make a public announcement to passengers about the emergency situation.