Narrative:

In climb to FL340; ATC queried if we could accept FL360 for a final altitude due to faster traffic behind us. Speed card indicated FL360 was within limits for 48;000 pounds. Leveled off momentarily at FL340; [and] then accepted climb clearance for FL360. Shallowed out end of the climb from 500 ft/min. Once level; even at climb thrust; aircraft began to loose airspeed at a rate even quicker than in the climb. First officer requested lower altitude from ATC. I disconnected the autopilot; and began a descent; after which stick shaker momentarily went off. Advised first officer to declare an emergency; but then immediately afterwards received ATC clearance down to FL350; then FL340 and flight continued normally. As a result of low airspeed in the climb; a heavy fuel/passenger load; and an 11 degree warmer than standard day; the aircraft leveled off slow and behind the power curve; unable to maintain airspeed or accelerate even with full thrust. This was certainly an eye-opening; humbling lesson learned the hard way in high altitude aerodynamics. With routinely sluggish 200 climb performance it's easy to become complacent with checking the speed card/ACARS for altitude ability without enough attention paid to the associated minimum published airspeeds. As PIC in this instance; I should have maintained FL340 until enough airspeed was regained to not jeopardize leveling off at FL360 slow and behind the power curve in an unsafe situation. Certainly won't be inadvertently repeated.

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Original NASA ASRS Text

Title: A CRJ200 attempted a climb to FL360 but because the aircraft was heavy with the temperature ISA +11; it could not climb above FL350 and an emergency was declared for an immediate descent after a stall warning.

Narrative: In climb to FL340; ATC queried if we could accept FL360 for a final altitude due to faster traffic behind us. Speed card indicated FL360 was within limits for 48;000 LBS. Leveled off momentarily at FL340; [and] then accepted climb clearance for FL360. Shallowed out end of the climb from 500 FT/min. Once level; even at climb thrust; aircraft began to loose airspeed at a rate even quicker than in the climb. First Officer requested lower altitude from ATC. I disconnected the autopilot; and began a descent; after which stick shaker momentarily went off. Advised First Officer to declare an emergency; but then immediately afterwards received ATC clearance down to FL350; then FL340 and flight continued normally. As a result of low airspeed in the climb; a heavy fuel/passenger load; and an 11 degree warmer than standard day; the aircraft leveled off slow and behind the power curve; unable to maintain airspeed or accelerate even with full thrust. This was certainly an eye-opening; humbling lesson learned the hard way in high altitude aerodynamics. With routinely sluggish 200 climb performance it's easy to become complacent with checking the speed card/ACARS for altitude ability without enough attention paid to the associated minimum published airspeeds. As PIC in this instance; I should have maintained FL340 until enough airspeed was regained to not jeopardize leveling off at FL360 slow and behind the power curve in an unsafe situation. Certainly won't be inadvertently repeated.

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.