The violent commotion resulted in several injuries among passengers and crew.
New Delhi:
Last week, Singapore Airlines flight SQ321, en route from London to Singapore, was dramatically hit by severe turbulence while cruising at 37,000 feet over Myanmar. Preliminary findings released by Singapore’s Transport Safety Investigation Bureau (TSIB) provide a detailed account of the incident that reveals the violent nature of the turbulence and its aftermath.
On May 21, Boeing 777-300ER SQ321, carrying 211 passengers and 18 crew, encountered unexpected and severe turbulence. The sudden turbulence resulted in one death, a suspected heart attack for one passenger, and numerous injuries among those on board. The plane made an emergency landing in Bangkok, the capital of Thailand.
“The aircraft experienced a rapid change in G (gravitational force), which may have resulted in the aircraft becoming airborne without wearing a belt,” Singapore’s Ministry of Transport said in a statement, citing a report by Singapore’s Transport Safety Investigation Bureau. .
According to TSIB findings, flight SQ321 took off from London on May 20 and maintained a normal flight path until the turbulence incident.
The investigation revealed that the gravitational force (G-force) fluctuated between +0.44G and +1.57G over 19 seconds, which caused the initial vibrations. The aircraft experienced an uncommanded altitude of 37,362 feet, which may have been due to development. The autopilot attempted to correct this by pitching the aircraft down, and the pilots increased uncommanded airspeed by extending the speed brakes.
“The vertical acceleration changed from negative 1.5G to positive 1.5G in less than 4 seconds, resulting in the airborne occupants falling back down. The rapid changes in G in 4.6 seconds caused a height drop of 178 feet (54 m), from 37,362 feet to 37,184 feet. This sequence of events indicated that the crew and may cause injuries to passengers,” the report said.
How did the crew respond?
During the turbulence, the pilots disengaged the autopilot and stabilized the aircraft manually for 21 seconds.
They re-engaged the autopilot at 07:50:05 UTC and the aircraft returned to an altitude of 37,000 feet by 07:50:23 UTC.
After assessing the injuries and the severity of the situation, the pilots diverted the aircraft to Suvarnabhumi Airport in Bangkok.
They coordinated with air traffic control to ensure medical services were ready upon landing.
The aircraft initiated a controlled descent at 08:06 UTC and landed safely at 08:45 UTC without encountering severe turbulence.
The violent commotion resulted in several injuries among passengers and crew. G-forces and sudden changes in altitude throw unprotected people against the cabin structure, causing severe shock. Unfortunately, one passenger suffered a suspected heart attack and could not be revived.
The TSIB, along with the National Transportation Safety Board (NTSB), the Federal Aviation Administration (FAA) and Boeing, are continuing to investigate the incident. Data from the Flight Data Recorder (FDR) and Cockpit Voice Recorder (CVR) have been analyzed to compile a detailed timeline of the event.
“We are committed to supporting our passengers and crew and their families and loved ones who were on board flight SQ321 that day,” Singapore Airlines said in a statement on Wednesday.
