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787 first officer reported encountering a wind shear at fl 400 resulting in airspeed exceedance; deviation from assigned altitude and loss of auto throttles.
| Attributes | |
| ACN | 1615341 |
| Time | |
| Date | 201902 |
| Environment | |
| Flight Conditions | VMC |
| Aircraft 1 | |
| Make Model Name | B787 Dreamliner Undifferentiated or Other Model |
| Operating Under FAR Part | Part 121 |
| Flight Phase | Cruise |
| Route In Use | Other oceanic |
| Flight Plan | IFR |
| Person 1 | |
| Function | First Officer Pilot Not Flying |
| Qualification | Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument Flight Crew Multiengine |
| Experience | Flight Crew Last 90 Days 126 Flight Crew Total 8854 Flight Crew Type 1486 |
| Events | |
| Anomaly | 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 |
Narrative:
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.
Original NASA ASRS Text
Title: 787 First Officer reported encountering a wind shear at FL 400 resulting in airspeed exceedance; deviation from assigned altitude and loss of auto throttles.
Narrative: 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.
Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.