Narrative:

We slowed to .76 mach to work through thunderstorms. Autothrottles did not hold speed. We went to maximum continuous power -- still above minimum maneuvering speed. Speed would not recover. After several mins; it continued to deteriorate. Getting very near stick shaker; I ordered first officer to descend. Radio was very busy. We were at FL384 before getting clearance to FL370. The controller did not seem alarmed.

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Original NASA ASRS Text

Title: B737-800 IS UNABLE TO MAINTAIN AIRSPD AT FL390 WHILE MANEUVERING FOR WX.

Narrative: WE SLOWED TO .76 MACH TO WORK THROUGH TSTMS. AUTOTHROTTLES DID NOT HOLD SPD. WE WENT TO MAX CONTINUOUS PWR -- STILL ABOVE MINIMUM MANEUVERING SPD. SPD WOULD NOT RECOVER. AFTER SEVERAL MINS; IT CONTINUED TO DETERIORATE. GETTING VERY NEAR STICK SHAKER; I ORDERED FO TO DSND. RADIO WAS VERY BUSY. WE WERE AT FL384 BEFORE GETTING CLRNC TO FL370. THE CTLR DID NOT SEEM ALARMED.

Data retrieved from NASA's ASRS site as of January 2009 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.