B737-800
Flight Crew Air Transport Pilot (ATP)
Situational Awareness
Deviation - Speed All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Weather / Turbulence
Flight Crew Regained Aircraft Control; Flight Crew Took Evasive Action
Human Factors; Procedure
While climbing up to FL360; we were in light to moderate turbulence for the majority of the climb. At some point; the Captain who was also flying pilot selected Airspeed Intervention of 270 to slow for the turbulence and expedite our climb. At approximately FL340; I noticed a 'buffet alert' message in the scratch pad of my FMC. As I noticed the airspeed at the top of the yellow arc; the Captain disconnected the autopilot; lowered the nose; and advanced the throttles. At the same time we encountered more turbulence and the airspeed continued to decrease to the point where we got a momentary stick shaker. The airspeed then accelerated rapidly and we resumed our climb to FL360. We estimate that the recovery process resulted in a loss of 200-300 FT. Should not have used Airspeed Intervention; should have used 280/.76 in the climb page and VNAV.
A B737-800 Captain selected MCP SPD during climb in moderate turbulence and later a FMC 'BUFFETT ALERT' was noticed; followed by airspeed in the yellow arc. The autopilot was disconnect and a stall recovery completed with a 200-300 FT altitude loss.