Boeing 747-400, VH-ANA

The pilot in command of the Boeing 747 reported that while cruising at flight level 380 the aircraft encountered clear air turbulence. Although the weather forecast indicated active thunderstorms within 110 NM of the track being flown, turbulence was not forecast nor was there any indication, either visually or via the radar, that turbulence was imminent. The seat belt sign was not illuminated at the time, nor was it required to be illuminated.

Cabin crew reported that a passenger sustained a suspected broken ankle while exiting a lavatory. Another passenger, who was waiting to enter a lavatory, sustained a suspected sprained ankle. There were no other reports of injuries.