(Aircraft) Encountered About 2 Seconds Of Severe Turbulence Within The Cloud

Location: Atlanta, GA Accident Number: DCA23FA428
Date & Time: August 29, 2023, 18:31 Local Registration: N576DZ
Aircraft: Airbus SAS A350-941 Injuries: 4 Serious, 13 Minor, 148 None
Flight Conducted Under: Part 121: Air carrier - Scheduled

On August 29, 2023, about 1831 Eastern daylight time, Delta Air Lines (DAL) flight 175, an Airbus A350-941 experienced turbulence during descent into Hartsfield Jackson International Airport (ATL), Atlanta, Georgia. Of the 14 crew and 151 passengers onboard, 2 crew and 2 passengers sustained serious injuries, and 8 crew and 5 passengers sustained minor injuries. The aircraft sustained minor damage. DAL175 was a 14 Code of Federal Regulations (CFR) Part 121 scheduled international passenger flight from Milan Malpensa Airport (MXP), Milan, Italy to ATL.

The aircraft was flying the OZZZI 1 arrival into ATL with the seatbelt sign illuminated in the cabin. About 10 miles prior to reaching the OZZZI intersection, the flight crew stated they identified a weather radar return about 40 miles ahead near the KILRR intersection and requested a deviation from air traffic control (ATC) about 1827. The air traffic controller requested the aircraft continue to OZZZI before deviating north and the flight crew accepted this instruction noting only a small white cloud near OZZZI. The flight crew stated there were no PIREPs from preceding aircraft, no nearby weather radar returns, nor any significant turbulence indications on their Flight Weather Viewer application. The relief pilot contacted the flight attendants to inform them that they may encounter turbulence in about 5 minutes and suggested they complete their duties within that time.

Within about 4 minutes, about 1831, the aircraft entered about 12 seconds of instrument meteorological conditions (IMC) at about 14,000 feet and encountered about 2 seconds of severe turbulence within the cloud. The flight crew were notified of injuries in the cabin, declared an emergency with ATC, and requested emergency medical service (EMS) upon arrival in Atlanta. EMS personnel met the aircraft at the gate, and about 11 people were transported to the hospital for further evaluation.

A preliminary weather evaluation was conducted by the NTSB post-flight. NTSB specialties investigating this accident: air traffic control, meteorology, cockpit voice recorder, and flight data recorder. Interviews were conducted with air traffic control personnel. Parties to the investigation include the Federal Aviation Administration (FAA), Delta Air Lines and the National Air Traffic Controllers Association (NATCA). In accordance with the provisions of Annex 13 to the Convention on International Civil Aviation, an Accredited Representative from the Bureau d'Enquêtes et d'Analyses (BEA) of France, the State of Design and Manufacture of the aircraft, was appointed to support the investigation, with Airbus as a technical advisor.

FMI: www.ntsb.gov