B787 Dreamliner Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 126; Flight Crew Total 8854; Flight Crew Type 1486
Situational Awareness; Workload
Aircraft Equipment Problem Less Severe; Deviation - Altitude Excursion From Assigned Altitude; Deviation - Speed All Types; Inflight Event / Encounter Loss Of Aircraft Control; Inflight Event / Encounter Weather / Turbulence
Weather
Between 135W & 134W on our route of flight at FL 400 we encountered an unexpected windshear event with some moderate turbulence. Autothrottles unable to keep up with shear event had to be overridden. Aircraft started a rapid climb and autopilot and lateral navigation disconnected on its own. Altitude deviations of plus and minus 800 feet occurred. Estimated sudden shear event of 30 knots or more. Aircraft exceeded VMO/MMO by 10-15 knots. Total duration of event approximately 1.5 minutes.
787 First Officer reported encountering a wind shear at FL 400 resulting in airspeed exceedance; deviation from assigned altitude and loss of auto throttles.