Incident
United Airlines Flight 820, en route from Norita, Japan to San Francisco, California, experienced severe clear air turbulence while cruising at flight level 380. The turbulence occurred abruptly and without warning, according to reports from both the flight and cabin crews. The seat belt sign was off at the time of the encounter.
Injuries
Three cabin crew members were thrown to the ceiling as a result of the turbulence. Two of them sustained injuries, with one suffering a fractured leg. The extent of the other crew member's injuries was not specified. No passengers were reported injured in the incident.
Diversion
Following the turbulence encounter, the flight crew decided to divert the aircraft to Honolulu, Hawaii. The aircraft landed without further incident. The flight crew and cabin crew both stated that there had been no indication of impending turbulence prior to the sudden encounter that led to the injuries.