A Cloud Shot Up Vertically (Like A Smoke Plume) In Front Of The Airplane In A Matter Of Seconds

Location: Kahului, HI Accident Number: DCA23LA096
Date & Time: December 18, 2022, 10:07 Local Registration: N393HA
Aircraft: Airbus A330-243 Injuries: 6 Serious, 19 Minor, 266 None
Flight Conducted Under: Part 121: Air carrier - Scheduled

On December 18, 2022, about 10:07am HST (20:07 UTC), Hawaiian Airlines flight 35, an Airbus A330-200, N393HA, experienced severe convectively induced turbulence at flight level (FL) 400, about 65 nm NNE of Kahului, Maui, Hawaii, about 40 minutes from landing at Honolulu International Airport (HNL), Honolulu, Hawaii. Of the 291 passengers and crew, there were 25 injuries, of which 6 were serious. The airplane received minor damage. The regularly scheduled domestic passenger flight was operating under the provisions of 14 Code of Federal Regulations Part 121 from Phoenix, Arizona (KPHX).

The first officer was the pilot flying and the captain was the pilot monitoring. The captain stated that they were in visual meteorological conditions (VMC) at FL400 and were above a cirrostratus cloud layer that was about 37,000 to 38,000 feet. He stated that flight conditions were smooth with clear skies above the cirrostratus layer and the on-board weather radar was on and set to “ALL” with no returns displayed on radar. A cloud shot up vertically (like a smoke plume) in front of the airplane in a matter of seconds, and there was not enough time to deviate. He called the lead flight attendant to advise her that they may have turbulence. Within about 1 to 3 seconds, he said the airplane encountered severe turbulence. Shortly after the turbulence-related upset, the lead flight attendant informed the flight crew that there were multiple injuries in the cabin.

Postaccident examination of the weather in the area revealed that there was an occluded frontal system with an associated upper-level trough moving towards the Hawaiian Islands. Satellite and weather radar imagery, and lightning data depicted strong cells in the vicinity of the flight. The U.S National Weather Service (NWS) had issued current Significant Meteorological (SIGMET) warning for embedded thunderstorms with tops reaching FL380 over the region. There were no pilot reports of severe turbulence along the route prior to the accident.

FMI: www.ntsb.gov