A B737-800 captain selected MCP speed during climb in moderate turbulence and later a FMC 'buffett a...

Attributes
ACN	1002623
Time
Date	201203
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZZ.ARTCC
State Reference	FO
Environment
Light	Daylight
Aircraft 1
Make Model Name	B737-800
Operating Under FAR Part	Part 121
Flight Phase	Climb
Flight Plan	IFR
Component
Aircraft Component	Autothrottle/Speed Control
Person 1
Function	First Officer Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Deviation - Procedural Published Material / Policy Deviation - Speed All Types Inflight Event / Encounter Weather / Turbulence

Narrative:

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.

Original NASA ASRS Text

Title: 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.

Narrative: 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.

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.

A B737-800 captain selected MCP speed 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.