Narrative:

Acting as CFI, my student and I took runway 18, the active, for takeoff. We were told to make our north departure from a right downwind. While turning crosswind we experienced engine roughness and applied carburetor heat with no results. I took command of the aircraft and declared an emergency to runway 5 which ended in an uneventful landing. The aircraft was checked out by our maintenance personnel and no problems were evident during a run-up and test flight. The cause was believed to be carburetor ice.

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Original NASA ASRS Text

Title: INSTRUCTOR PLT WITH STUDENT PLT HAS ROUGH ENG ON INITIAL CLB. EMER DECLARED RETURN LAND. MAINT INSPECTION INDICATES POSSIBLE CARB ICE.

Narrative: ACTING AS CFI, MY STUDENT AND I TOOK RWY 18, THE ACTIVE, FOR TKOF. WE WERE TOLD TO MAKE OUR N DEP FROM A R DOWNWIND. WHILE TURNING XWIND WE EXPERIENCED ENG ROUGHNESS AND APPLIED CARB HEAT WITH NO RESULTS. I TOOK COMMAND OF THE ACFT AND DECLARED AN EMER TO RWY 5 WHICH ENDED IN AN UNEVENTFUL LNDG. THE ACFT WAS CHKED OUT BY OUR MAINT PERSONNEL AND NO PROBS WERE EVIDENT DURING A RUN-UP AND TEST FLT. THE CAUSE WAS BELIEVED TO BE CARB ICE.

Data retrieved from NASA's ASRS site as of July 2007 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.