Avianca A332 over Caribbean Sea on Jun 27th 2015, turbulence injures 38

Last Update: August 22, 2018 / 16:26:09 GMT/Zulu time

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Photo of Avianca N973AV, Airbus A330-200 — Avianca N973AV, Airbus A330-200 (Photo credit: airlines470 / Flickr / License: CC by-sa)

Incident Facts

Date of incident
Jun 27, 2015

Classification
Accident

Cause
Turbulence

Airline
Avianca

Flight number
AV-18

Departure
Bogota, Colombia

Destination
Barcelona, Spain

Aircraft Registration
N973AV

Aircraft Type
Airbus A330-200

ICAO Type Designator
A332

An Avianca Airbus A330-200, registration N973AV performing flight AV-18 (dep Jun 26th) from Bogota (Colombia) to Barcelona,SP (Spain) with 253 passengers and 13 crew, was enroute at FL390 over the Caribbean Sea about 400nm eastnortheast of Curacao (Curacao) and about 100nm southwest of Guadeloupe (Guadeloupe) at about 04:30Z when the crew descended the aircraft to FL360 reporting turbulence caused injuries to a number of occupants about 190nm southwest of Guadeloupe (N13.996 W63.772). The crew decided to turn around and divert to Curacao where the aircraft landed safely about 80 minutes later. 38 occupants received serious injuries and were taken to a hospital.

The airline reported the aircraft encountered turbulence of 4 seconds in Venezuelean airspace and confirmed 7 occupants were taken to a hospital, 6 could already be discharged, one flight attendant remained in hospital for observation following a hard hit with her head.

A replacement Airbus A330-200 registration N974AV positioned to Curacao as flight AV9982 and departed to continue flight AV-18 about 13.5 hours after landing.

On Jul 16th 2015 the French BEA reported in their weekly bulletin, that there were 38 serious injuries amongst the 266 occupants (247 passengers, 19 crew) of the aircraft.

On Jul 17th 2015 Colombia's GRIAA released a preliminary report in Spanish reporting the aircraft was enroute at FL370 on Airway UA550 at position N13.996 W63.772 with 253 passengers and 13 crew, when the aircraft encountered severe turbulence causing minor injuries to 38 occupants, 29 passengers and 9 cabin crew. At the time the crew observed a green indication on the weather radar confirmed by visual contact with a cloud cap underneath the flight path of the aircraft. While flying above the top of clouds the aircraft experienced severe turbulence causing a vertical acceleration of +1.7G followed by a wind change from 040 to 135 degrees within 6 seconds while crossing atmosphere interacting with the passage of a tropical wave.

In August 2018 the GRIAA released their final report in Spanish concluding the probable causes of the accident were:

- Overconfidence and lack of assertiveness by the crew by failing to comply with the recommendations by Airbus, Rockwell Collins and their airline to avoid overflying storm cells and to consider storm cells above FL350 as highly dangerous.

- High degree of compacency by the crew by not applying the recommended techniques and good practises in using the weather radar WXR-2100 to evaluate the type of clouds and their vertical development with greater assertiveness. The clouds were visible to the crew forward and below of the flight trajectory.

- The failure to comply with Airbus and airline recommendations, in order to protect passengers and cabin crew, to turn on the fasten seat belt signs and initiate an according announcement to the cabin when turbulence was to be expected which warranted alert, suspension of on board services and secure people in their seats to avoid injuries.

The GRIAA analysed that the use of the weather radar in automatic mode was appropriate until the aircraft until about 16 minutes before the turbulence encounter. The crew did not actively explore the type of clouds visible ahead and their vertical development and thus limited themselves considerably in acquisition of value information, that would have allowed the crew to assess the weather ahead, determine the risk associated with maintaining course and altitude and thus did not determine sufficient arguments to alter course and/or flight level. About 27nm before the weather the crew did still not react when the weather appeared to be fading away due to the inclination of the weather radar, no decision was made to delve into what was really ahead. The crew finally decided to not change course about 7.5nm before the weather - this decision at this point was correct because of the more severe consequences should the aircraft hit severe turbulence at a bank angle.

The GRIAA listed the six "unfulfilled recommendations", that the crew did not follow:

1. Crew should consider storm cells above FL350 as highly dangerous and must apply an additional 20nm clearance.
2. If the top of a storm cell is at or above FL250, the crew must not overfly it, otherwise the aircraft might encounter turblence stronger than anticipated
3. Crews should not dismiss a high expansion vertical storm cell even though its reflectivity and returns are low or mild.
4. In relation to the tilt control at high altitudes (FL250 and above) the Collins Manual, Operators Guide, mentions on page 4-70 that tops of storm cells can be invisible to radar. When the external temperature is below -40 degrees C, the storm tops are formed by crystals whose reflectivity is very low.
5. The manual mode is being used to determine the tilt angle in reflective areas of the cells, so that determination can be made about the cloud cap being less than 5000 feet. The main recommendation is to begin the tilt scan at the lowest point of the cloud and then progressively raise the tilt to detect the point at which the weather becomes nearly invisible.
6. Crews should not attempt to enter a storm cell or fly over its top at less than 5000 feet above because the aircraft might encounter severe turbulence.

The GRIAA analysed that standard operating procedures by the airline strictly prohibited flight crews to perform any other task than related to controlling the aircraft while on the flight deck, in particular crews were not permitted to listen to music even though possible to receiver via the ADF receivers. During the last 1:30 hours of flight prior to the encounter music was clearly recorded on the CVR, several frequency changes on the ADF receiver not assoicated with NDB/ADF operations were recorded on the FDR. The FDR and CVR also showed that the volume of the ADF #2 was turned down and turned up again in order to not affect communications with ATC Maiquetia and ATC Piarco as well as post the turbuelence encounter when the crew communicated the emergency and injuries to ATC.

The GRIAA analysed that following the turbulence encounter the crew performed a very good emergency management.