B787 Dreamliner Undifferentiated or Other Model
Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 127; Flight Crew Total 3889; Flight Crew Type 2439
Deviation - Altitude Excursion From Assigned Altitude; Deviation - Speed All Types; Inflight Event / Encounter Weather / Turbulence; Inflight Event / Encounter Loss Of Aircraft Control
Flight Crew Regained Aircraft Control; Flight Crew Returned To Clearance
Weather
Was in the bunk on crew rest when aircraft experienced severe turbulence. On returning to the flight deck crew informed me of severe turbulence event with uncontrollable flight; VMO/MMO exceeded by 20 kts; mountain wave; TCAS EVENT. No injuries to crew or passengers. Aircraft written up for inspection. I have no additional information on the event.
B787 Relief First Officer reported the aircraft encountered severe turbulence in cruise flight; resulting in temporary loss of control and airspeed and altitude deviations.