MD-11
Flight Crew Air Transport Pilot (ATP)
Deviation - Altitude Excursion From Assigned Altitude; Inflight Event / Encounter Loss Of Aircraft Control; Inflight Event / Encounter Weather / Turbulence
Air Traffic Control Issued New Clearance; Flight Crew Regained Aircraft Control; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Took Evasive Action; General Maintenance Action
Weather
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.
[We] encountered severe turbulence just west of London; England at FL320. [We were] unable to maintain altitude. Stick shaker activated twice. Called London Control 300 FT off altitude and received a clearance down to FL300.
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.