THE AIRPLANE WAS ON BASE LEG ABOUT ONE MILE FROM THE AIRPORT WHEN CARBURETOR HEAT WAS APPLIED. THE ENGINE SURGED AND THEN LOST POWER, AND WAS NOT RESTARTED. THE AIRPLANE DESCENDED AND IMPACTED IN A NOSE LOW, LEFT WING LOW ATTITUDE. NO EVIDENCE OF A PRE-EXISTING FAILURE OR MALFUNCTION WAS FOUND. THE TEMPERATURE 11 MILES AWAY WAS RECORDED AT 89 DEGREES F AND THE DEWPOINT AT 68 DEGREES F.