Narrative:

ATC facility: ZMA. Location: south of nassau. Had just been cleared to climb out of FL290 to FL330. Started climb and selected engine anti-ice due to temperature and clouds. First officer asked me if I smelled anything. I don't have a keen sense of smell, but could make out acrid smell seemingly electrical in nature. Put on masks and got a call from the back about the smell. Worked procedure and also turned off anti-ice as we were clear of clouds for the moment. Declared emergency and requested return to mia. Smell dissipated very quickly in cockpit and cabin. Suspect it was from anti-ice. Overweight landing in mia was normal. No substitute equipment so flight was canceled.

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Original NASA ASRS Text

Title: ELECTRICAL ODORS IN COCKPIT AND CABIN AFTER ENG ANTI-ICE TURNED ON COMPELS THE PIC OF A B757 TO RETURN LAND AT MIA, FL.

Narrative: ATC FACILITY: ZMA. LOCATION: S OF NASSAU. HAD JUST BEEN CLRED TO CLB OUT OF FL290 TO FL330. STARTED CLB AND SELECTED ENG ANTI-ICE DUE TO TEMP AND CLOUDS. FO ASKED ME IF I SMELLED ANYTHING. I DON'T HAVE A KEEN SENSE OF SMELL, BUT COULD MAKE OUT ACRID SMELL SEEMINGLY ELECTRICAL IN NATURE. PUT ON MASKS AND GOT A CALL FROM THE BACK ABOUT THE SMELL. WORKED PROC AND ALSO TURNED OFF ANTI-ICE AS WE WERE CLR OF CLOUDS FOR THE MOMENT. DECLARED EMER AND REQUESTED RETURN TO MIA. SMELL DISSIPATED VERY QUICKLY IN COCKPIT AND CABIN. SUSPECT IT WAS FROM ANTI-ICE. OVERWT LNDG IN MIA WAS NORMAL. NO SUBSTITUTE EQUIP SO FLT WAS CANCELED.

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.