History of Flight
On 7 June 2021, Vistara flight operating a Boeing 737-800 aircraft, registration VT-TGE, departed from Mumbai (runway 14) en route to Kolkata. The flight crew consisted of a Pilot-in-Command (PIC) holding an Airline Transport Pilot License (ATPL) and a Co-pilot (F/O) holding a Commercial Pilot License (CPL). The PIC acted as Pilot Monitoring (PM) and the F/O as Pilot Flying (PF). The aircraft carried 120 persons on board, including six crew members.
The flight was uneventful during climb and cruise. At 1022 UTC, the crew obtained Kolkata weather via ACARS, which indicated TSRA (thunderstorms with rain) and gusty winds. Guwahati and Bhubaneswar were planned alternates. The PF made a passenger announcement about expected turbulence and instructed the Senior Cabin Crew (SCC) to secure the cabin early.
During descent from FL390, the aircraft deviated approximately 20 NM right of the assigned track to avoid cumulonimbus (CB) clouds and line squalls. The crew identified a 20 NM gap between two CBs and decided to fly through it. Shortly after descent began, the SCC informed the cockpit that a passenger wished to use the lavatory, and the PM turned off the seat belt sign temporarily. At approximately FL260, the seat belt sign was reactivated as a precaution. The cabin crew began securing the cabin and making announcements, but the PIC then instructed the cabin crew to be seated due to anticipated turbulence. Consequently, the seat belt compliance check of the entire cabin could not be completed.
About two minutes after the crew were advised to be seated, the aircraft experienced light to moderate turbulence. This lasted 10–15 seconds and culminated in a severe turbulence bump lasting 1–2 seconds. The autopilot disconnected momentarily and was re-engaged. No exceedances were observed except a brief bank angle warning. After the bump, the aircraft encountered no further turbulence.
The PM inquired about the cabin, and the SCC reported injured passengers. The seat belt sign was turned off, and crew assisted the injured. A doctor on board attended to them. The crew informed Kolkata ATC and requested a medical priority landing and ambulance services. The aircraft landed safely on runway 19R at Kolkata. Four passengers sustained injuries: two serious (seats 39D and 26A) and two minor (seats 26B and 30B).
Injuries to Persons
- Crew: None
- Passengers: 2 serious, 2 minor
- Others: None
Damage to Aircraft
Two ceiling panels and two overhead center distribution duct (nozzle/plenum duct) were damaged at multiple locations due to passengers hitting the ceiling during turbulence.
Personnel Information
The PIC was 39 years old, held an ATPL valid until 24 June 2025, with total flying experience of 9300 hours (9050 hours on type, 5600 hours as PIC). The F/O was 30 years old and held a CPL. Both crew had valid medical certificates and had adequate rest before duty.
Weather and Flight Crew Actions
Kolkata ATIS reported TSRA and gusty winds at the expected time of arrival. The crew deviated right of track to avoid CBs and line squalls, then flew through a gap between two CBs. The severe turbulence encountered during this passage led to injuries and minor aircraft damage.