India B788 near Amritsar on Apr 19th 2018, turbulence injures three

Last Update: July 5, 2019 / 16:00:17 GMT/Zulu time

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Photo of Air India VT-ANI, Boeing 787-8 Dreamliner — Air India VT-ANI, Boeing 787-8 Dreamliner (Photo credit: markyharky / Flickr / License: CC by)

Incident Facts

Date of incident
Apr 19, 2018

Classification
Accident

Cause
Turbulence

Airline
Air India

Flight number
AI-462

Departure
Amritsar, India

Destination
Delhi, India

Aircraft Registration
VT-ANI

Aircraft Type
Boeing 787-8 Dreamliner

ICAO Type Designator
B788

An Air India Boeing 787-800, registration VT-ANI performing flight AI-462 from Amritsar to Delhi (India) with 244 passengers and 10 crew, was climbing out of Amritsar between 8000 feet and FL210 at about 14:58L (09:28Z) when the aircraft encountered turbulence causing injuries to three passengers, several passenger service units to drop and an interior window to separate. Cabin crew remounted the window in flight, the aircraft continued to Delhi for a safe landing. The three injured passengers were taken to a hospital.

The aircraft remained on the ground in Delhi for about 24 hours until returning to service.

India's media report one of the passengers had not fastened his seat belt and bumped his head against a luggage compartment. The aircraft is said to have experienced vertical accelerations up to 3G in flight as result of the turbulence, the aircraft did not receive any structural damage.

The airline reported the aircraft encountered severe clear air turbulence. Two passengers received minor injuries, another one needed several stitches. All passengers were able to continue on their connecting flights after receiving medical assistance.

India's DGCA opened an investigation into the occurrence.

On Jul 5th 2019 the DGCA released their final report concluding the probable causes of the occurrence were:

Flight crew did not appropriately assess the weather conditions before departure from Amritsar and encountered severe turbulence during climb which resulted into passenger injuries and damage to the cabin furnishing.

The DGCA reported three passengers received minor injuries in the tutbulence encounter producing vertical accelerations between +1.778 and -1.307G. The DGCA described the damage to the aircraft: "Passenger Service Unit near seat no. 12 E got damaged. Several Passenger Service Units also dropped and window decorative panel on seat no. 18 A got separated during turbulence. "

The first officer (36, ATPL, 4,976 hours total, 3,126 hours on type) was pilot flying, the captain (43, ATPL, 5,646 hours total, 3,393 hours on type) was pilot monitoring.

The DGCA analysed:

Weather:

- As per weather report of Amritsar airport from 0800 UTC to 0830 UTC, there was light wind, few clouds at 4000ft, scattered clouds at 10,000ft and Visibility was reported as 5000M with Trend forecast issued as NOSIG. In METAR of 0900 UTC, Few CB at 3500 ft was included with light wind, visibility 5000m and weather Thunderstorm with Trend forecast issued as TEMPO 310220G32KT 1200 DS. In METAR of 0930 UTC, It was a feeble thunderstorm with rain and wind from 300 DEG direction, visibility 3000M, SCT clouds at 9000ft, Few CB at 1050ft, Broken clouds at 10000ft with Trend forecast as TEMPO 31020G3OKT 1200 DS. In METAR of 1000UTC, current weather was reported as FBL TSRA with SCT and Broken clouds with FEW CB , Visibility 3000M with Trend forecast as NOSIG. In METAR of 1030 UTC to 1100UTC, weather was reported as HAZE; Visibility 3500M and SCT clouds at 1050 FT and SCT clouds at 2700ft.

- INSAT 3D images for both VIS (VISIBLE)/IR (INFRARED) for 19.4.2018 from 0800 UTC to 0930 UTC confirms the formation and intensification of convective and CB clouds from 0800 UTC onwards at and around Amritsar aerodrome during the period.

- DWR (Doppler Weather Radar) pictures of Patiala from 0812 UTC to 0922UTC confirms that CB cells already observed in the DWR at south-southwest sector of Amritsar as early as 0812UTC of 19 April 2018 and by 0832 to 0902UTC, it had intensified into a very big CB cell with a bubble type sudden growth type and formation of large-scale CB. The TS occurred as per current weather and as per DWR of 0922UTC, it is observed that the associated CB had vertical altitude of 14-15km and hence must have created very high wind shear or a CB cloud caused moderate to severe updraft/downdraft over the airport which have caused moderate/severe turbulence at and around the airport.

- From the above it is inferred that the flight took off from Amritsar at 09:23 UTC in adverse weather condition (CB/thunderstorm). During climb due to presence of CB aircraft encountered severe turbulence.

Pilot handling of the situation:

- The previous flight (Delhi-Amritsar) was operated by the same set of operating crew and the flight was uneventful.

- During return sector (Amritsar-Delhi) according to the flight crew while passing from FL 80 to FL 210 aircraft encountered light to moderate turbulence which unexpectedly grew into severe turbulence. Due to the severity of the turbulence the aircraft experienced vertical accelerations from +1.778 G to -1.307 G. Once in severe turbulence, while passing through FL 180 autopilot got disengaged and the aircraft climbed almost 600 feet above the cleared level momentarily at this point controls were handed over from PF to 17 PM. Flight crew informed the ATC about the altitude burst and descended to assign FL 190. Thereafter aircraft continued to Delhi for a safe landing in coordination with ATC. CVR recording reveals that at the time of severe turbulence there was no standard call out for positive handing /taking over of the controls by the flight crew.

- Severe turbulence from Thunderstorm/tall active CB clouds observed over the airport had caused the aircraft to face this incident. The aircraft had taken off from RWY 34 at a time when the airport was under bad weather condition for which there was a Trend forecast and weather warning by 0900 UTC. It was summer season and the CB with Thunderstorms/ dust storms were already in peak occurrences at various airports of north India. The pilot did not refer DWR based CB detection system for live updates for all cloud products (reflectivity/max z) through the IMD and OLBS web page.

- METAR issued at Amritsar Airport from 0800 UTC to 1100 UTC indicates presence of CB cloud at 3500 feet. Flight crew did not take into account the bad weather at VIAR by timely weather updates. As per records in IMD AMSS (Automatic Message Switching System), the Met Briefmg folder/IMD products of DWR/INSAT/OLBS for this flight was not downloaded prior to the flight.

Circumstances leading to the incident:

As per weather report of Amritsar airport weather deteriorated to thunderstorms with rain and cumulonimbus cloud. The aircraft took off from Amritsar airport at 09:23 UTC under adverse weather condition. During initial climb passing FL 60 rapid weather build up was observed by the flight crew ahead and left of their flight path. While passing from FL 80 to FL 210 the light topoderate turbulence grew sever, the severe turbulence was encountered between FL160 and FL190. Once in severe turbulence, while passing through FL 180 auto pilot got disengaged.

After couple of attempts PIC re-engaged the autopilot, however the aircraft climbed almost 600 feet above the cleared level momentarily. Due to the severity of the turbulence encounter the aircraft experienced vertical accelerations from +1.778 G to -1.307 G and three passengers were injured and there was apparent damage to the cabin furnishings. Once clear of turbulence the aircraft continued to Delhi and landed safely.