History of the Flight
On 5 October 2014, Thai Airways Public Company Limited operated flight TG045 from Khon Kaen Airport to Suvarnabhumi Airport using an Airbus A330-322, registration HS-TEJ. The aircraft carried 10 crew and 177 passengers. At approximately 12:32 p.m. local time, the flight departed. During descent, the crew was cleared to descend to FL170, then to FL130. The pilot activated the seat belt sign at about 14,700 feet. At 12:55:31 p.m., the pilot requested a heading of 215 degrees due to weather. At 12:58:54 p.m., the aircraft was cleared to descend to 7,000 feet. The descent path passed between towering cumulus clouds with a thick layer connecting them, approximately 20–30 nautical miles from the glide path. The pilot activated the weather radar and maximized signal intensity using the Gain button, but the radar on both Navigation Displays did not indicate severe weather or turbulence. The pilot decided to fly between the clouds. While descending through 12,859–12,483 feet, the aircraft encountered severe turbulence twice between 01:00:46 p.m. and 01:01:01 p.m. Four flight attendants who were storing equipment in the aft galley were thrown up and fell, resulting in one serious spinal injury and three minor injuries. An additional flight attendant in the middle of the cabin sustained minor injuries. After landing, the pilot arranged for an ambulance and medical personnel at Suvarnabhumi Airport.
Injuries
One flight attendant suffered a serious injury (spinal). Four flight attendants sustained minor injuries. No passengers or other crew were injured. No fatalities.
Damage to Aircraft
None.
Personnel Information
The pilot, aged 41, held an Airline Transport Pilot Licence with 15,013 total flight hours, including 1,759 hours on the A330-300. The co-pilot, aged 32, also held an ATPL with 3,112 total flight hours, including 2,342 hours on the A330-300. Both had valid medical certificates and recent training.
Aircraft Information
The aircraft was an Airbus A330-322, serial number 209, manufactured in 2009. It was registered to Thai Airways and had a valid Certificate of Airworthiness. Total time since new was 55,479 hours. Engines were Pratt & Whitney PW4168. Maintenance checks were current.
Meteorological Information
METAR reports from Suvarnabhumi Airport at 12:00 p.m. and 1:00 p.m. indicated winds from 060–090 degrees at 9 knots with gusts up to 21 knots, visibility 10 km or more, few cumulonimbus clouds at 2,000 feet, and temperature 33°C. No significant change was forecast.
Conclusions from Investigation
The investigation's findings included that the aircraft encountered severe turbulence due to weather conditions while descending between towering cumulus clouds. The flight crew did not use the weather radar effectively to detect potential turbulence, and they did not receive adequate training or guidance in using weather radar for turbulence identification. The probable cause was the aircraft encountering severe turbulence due to weather conditions, with contributing factors being ineffective use of weather radar and inadequate training.