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An MD11 encountered severe clear air turbulence at FL320 causing both overspeed and stick shaker activation and some loss of altitude. A lower altitude was immediately requested and granted by ATC. The flight continued to destination.
| Attributes | |
| ACN | 1018367 |
| Time | |
| Date | 201206 |
| Local Time Of Day | 1801-2400 |
| Place | |
| Locale Reference | EGTT.ARTCC |
| State Reference | FO |
| Aircraft 1 | |
| Make Model Name | MD-11 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | Cruise |
| Person 1 | |
| Function | Pilot Not Flying Captain |
| Qualification | Flight Crew Air Transport Pilot (ATP) |
| Person 2 | |
| Function | First Officer Pilot Flying |
| Qualification | Flight Crew Air Transport Pilot (ATP) |
| Events | |
| Anomaly | Deviation - Altitude Excursion From Assigned Altitude Inflight Event / Encounter Loss Of Aircraft Control Inflight Event / Encounter Weather / Turbulence |
Narrative:
We were at cruise speed at FL320 in the vicinity of london slightly west of stansted on the way to oceanic airspace. The aircraft entered an area of severe clear air turbulence. Aircraft went into a high speed stall and rolled off to the left. I assumed the pilot flying responsibilities; disconnected the autopilot and began hand flying the aircraft to recover and told the first officer to contact london control and tell them we needed a lower altitude. FL300 was immediately given to us by london control and I began the controlled descent. Approximately 30 seconds after the first stall and recovery the aircraft stalled again into the low speed footer. I continued with the stall recovery and turned approximately 30 to 40 degrees to the left to exit the area. We established cruise at FL300; and after deciding the aircraft did not exhibit any adverse flight characteristics; I elected to continue to destination. Upon arrival; we wrote up the event in the aircraft log for post flight inspection.
Original NASA ASRS Text
Title: An MD11 encountered severe clear air turbulence at FL320 causing both overspeed and stick shaker activation and some loss of altitude. A lower altitude was immediately requested and granted by ATC. The flight continued to destination.
Narrative: We were at cruise speed at FL320 in the vicinity of London slightly west of Stansted on the way to Oceanic Airspace. The aircraft entered an area of severe clear air turbulence. Aircraft went into a high speed stall and rolled off to the left. I assumed the pilot flying responsibilities; disconnected the autopilot and began hand flying the aircraft to recover and told the First Officer to contact London Control and tell them we needed a lower altitude. FL300 was immediately given to us by London Control and I began the controlled descent. Approximately 30 seconds after the first stall and recovery the aircraft stalled again into the low speed footer. I continued with the stall recovery and turned approximately 30 to 40 degrees to the left to exit the area. We established cruise at FL300; and after deciding the aircraft did not exhibit any adverse flight characteristics; I elected to continue to destination. Upon arrival; we wrote up the event in the aircraft log for post flight inspection.
Data retrieved from NASA's ASRS site as of July 2013 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.