Flight History
On January 12, 2020, at 13:06 JST, Jin Air flight 262, a Boeing 737-800 registered as HL8243, departed from Kitakyushu Airport, Japan, bound for Incheon International Airport, South Korea. The aircraft carried 174 persons: one pilot in command (PIC), one first officer (FO), one trainee in FO promotion training, six cabin crew members including the purser, and 167 passengers. The PIC occupied the left seat as pilot monitoring, the trainee the right seat as pilot flying, and the FO the observer seat.
After reaching 10,000 ft during climb, the flight crew confirmed no shaking and visually cleared clouds, then turned off the seat belt sign around 13:12. The aircraft continued climbing to its planned cruising altitude of FL 320. Based on pre‑departure weather information, the PIC anticipated possible shaking and considered responses such as promptly re‑activating the seat belt sign.
In the cabin, after the sign was turned off, crew began selling duty‑free goods and distributing immigration cards. The purser moved to the aft galley.
Turbulence Encounter
At approximately 13:17, immediately after reaching FL 250, the aircraft experienced a sudden, strong shaking. The PIC immediately turned on the seat belt sign and instructed crew to be seated. During the shaking, the purser, who was standing in the center of the aft galley facing forward, fell to her right. She later confirmed pain in her right ankle and abrasions. Smaller shakings continued after the initial event; the aircraft stopped shaking after reaching FL 270. The flight crew reported the turbulence to Fukuoka Air Traffic Control. The autopilot had been engaged from initial climb until the turbulence and remained engaged during the event.
After the shaking ceased, the PIC received reports that no passengers or other crew were injured. He judged it possible to continue to Incheon, and the flight proceeded. The injured purser performed duties possible while seated. After arrival, the PIC interviewed her, and she was later diagnosed with a lateral malleolus fracture (right ankle fracture) at a hospital in Seoul.
Injuries and Damage
A cabin crew member (the purser) sustained a serious injury: a right ankle fracture. The aircraft was not damaged.
Flight Crew Information
PIC: Age 47, airline transport pilot certificate, Boeing 737 type rating, total flight time 8,593 hours (3,519 hours on type). FO: Age 36, commercial pilot certificate, Boeing 737 type rating, total flight time 2,110 hours (1,106 hours on type). Trainee: Age 34, commercial pilot certificate, Boeing 737 type rating, total flight time 1,150 hours (112 hours on type). All held valid medical certificates.
Aircraft Information
Aircraft: Boeing 737-800, serial number 38825, manufactured January 31, 2012. Certificate of airworthiness valid. At the time, weight was estimated at 137,760 lb and center of gravity at 26.0% MAC, both within allowable ranges.
Meteorological Conditions
Prior to departure, the flight crew reviewed an upper‑layer wind forecast chart (based on data from 03:00 JST on January 12). The chart showed areas of vertical wind shear (VWS) between 6 and 12 kt/1,000 ft, and between 12 and 15 kt/1,000 ft at altitudes from FL 240 to FL 270 along the planned route. Generally, VWS above 10 kt/1,000 ft can cause moderate turbulence, and above 15 kt/1,000 ft can cause severe turbulence. The forecast indicated VWS of 12 to 15 kt/1,000 ft in the area where the aircraft was climbing.
A cross‑section chart from the Japan Meteorological Agency (at 09:00 JST) showed a jet stream center near FL 320 north of Fukuoka, with wind velocity increasing by 20 kt per 1,000 ft above FL 240 over Fukuoka. No clouds that could produce turbulence were observed near the flight route. No pilot reports (PIREP) of turbulence in the area were received before the accident.
Flight Data Recorder (FDR) Data
FDR records indicated fluctuations in acceleration, flight attitude, and wind data between 13:17:14 and 13:17:26. Vertical acceleration, normally 1 G in calm, level flight, decreased from 1.19 G to 0.8 G between 13:17:14 and 13:17:15, then increased to 1.49 G by 13:17:16.