Primary finding
Probable cause
An encounter with turbulence during descent, which resulted in a serious injury to a flight attendant.
Investigator assessment
Analysis narrative
All Nippon Airways flight NH106, encountered severe turbulence during descent through FL140 (14,000 feet) to Los Angeles International Airport (LAX). As a result, multiple flight attendants (FAs) sustained minor injuries, and one FA sustained a serious injury. Prior to initiating descent, the flight crew obtained the Automatic Terminal Information Service (ATIS) for LAX, which did not include any turbulence advisories. Approximately 20 minutes before landing, air traffic control (ATC) advised the crew of light to moderate turbulence in the area. The pilot monitoring considered querying ATC for altitude-specific turbulence information, but the captain instructed the crew to illuminate the seat belt sign and have the FAs prepare the cabin for landing. While descending from FL200 to FL170, the aircraft encountered light turbulence. At approximately FL140, about 15 minutes before landing, the flight encountered two brief turbulence events, which the captain described as “moderate” and “moderate plus.” Following these encounters, the pilot monitoring recommended that FAs be seated, and the captain agreed. After the public announcement was made the flight crew was informed that multiple FAs had sustained injuries. During the initial turbulence encounter, the L3 FA was holding the lavatory handle for support. After the turbulence subsided, she proceeded to her assigned seat and began fastening her seat belt when the second turbulence encounter occurred. She was subsequently thrown into the air and landed on the cabin floor, impacting her buttocks. Upon returning to Japan, she was diagnosed with a serious injury. Figure 1. Location of cabin attendant that sustained a serious injury. At the time of the turbulence encounter, no convective Significant Meteorological Information (SIGMETs) were active. However, other advisories—including SIGMETs, Airmen’s Meteorological Information (AIRMETs), and Pilot Reports (PIREPs)—indicated moderate to severe turbulence in the vicinity of the flight path.