Flight Details
On 24 October 2017, a Boeing 737-800 aircraft registered PK-LBY operated by Batik Air as a scheduled passenger flight from Soekarno-Hatta International Airport (CGK/WIII) in Jakarta to Kualanamu International Airport (KNO/WIMM) in Medan, North Sumatera, Indonesia. The aircraft departed Jakarta at 0825 UTC (1525 local time) in daylight conditions. On board were two pilots, five cabin crew, and 114 passengers. The Pilot in Command (PIC) served as the Pilot Flying (PF), while the Second in Command (SIC) acted as Pilot Monitoring (PM). The aircraft cruised at an altitude of 36,000 feet (flight level 360) via route W12.
Encounter with Turbulence
During descent, the pilot maneuvered the aircraft to avoid clouds. The SIC turned on the fasten seat belt sign after noticing potential turbulence. At 0959 UTC, the aircraft encountered severe turbulence that lasted approximately 20 seconds. The autopilot disengaged unintentionally. Flight Data Recorder (FDR) data showed vertical acceleration ranging from 2.334 G to -0.482 G at an altitude of approximately 24,500 feet. The pilot flew manually for 17 seconds before continuing the descent and re-engaging the autopilot.
Aftermath
Following the turbulence, flight attendants inspected the cabin. One passenger was found injured in the aft lavatory, and a flight attendant (FA-5) was injured in the aft galley. Another flight attendant (FA-4) made two medical announcements, but no medical professionals were identified among the passengers. FA-3 informed the pilots of the cabin situation and the injuries.
The aircraft continued its descent, and the pilot communicated with air traffic control to avoid clouds. The flight was cleared as number four for landing. The pilot also contacted company operations personnel, reporting the severe turbulence and two injured occupants, and requested medical assistance upon arrival.
The aircraft landed safely at Kualanamu International Airport. The injured individuals were taken to the airport health facility and later transferred to a hospital outside the airport.
Safety Actions
The Komite Nasional Keselamatan Transportasi (KNKT) noted that Batik Air had taken safety actions in response to this occurrence, which the KNKT considered relevant to improving operational safety.