As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING BANNER TOW OPERATIONS, IN CRUISE FLIGHT AT APPROX 600' AGL, THE PILOT REPORTED THAT THE ENGINE STARTED TO SHUTTER VIOLENTLY AND SUBSEQUENTLY BEGAN TO RAPIDLY LOSE POWER. CARBURETOR HEAT WAS APPLIED WITH NO EFFECT. THE PILOT WAS FORCED TO PERFORM EMERGENCY DITCHING PROCEDURES.