Accident Overview
A pilot conducting a banner towing operation reported that ground crew attempted to connect the banner to the hook, but it failed to connect and became affixed to the tailwheel. The pilot performed several approaches over the banner field in an effort to dislodge the banner.
Sequence of Events
During the final attempt to release the banner, the pilot moved the throttle to idle and made a normal descent. The banner remained stuck to the tailwheel. The pilot then stopped the descent and advanced the throttle from idle to full power, at which point the engine sputtered without an increase in power. The pilot confirmed the mixture was in the full rich position and the primer was closed and locked. Two further attempts to move the throttle from idle to full power produced no change in engine response.
Forced Landing and Damage
The pilot executed a forced landing to the southwest corner of the field. The airplane collided with uneven terrain and trees. Substantial damage was sustained to both wings and the fuselage.
Pilot Report and Conditions
The pilot reported no mechanical malfunctions or failures that would have precluded normal operation. The temperature at the time was 80°F. The METAR from the nearest airport indicated a dew point of 72°F and relative humidity of about 77 percent.
Carburetor Heat Usage
During a post-accident interview, the pilot stated that carburetor heat was not used during the banner towing operation, including the low-power approaches to release the banner. According to the FAA Special Airworthiness Information Bulletin CE-09-35, carburetor heat is recommended in conditions of visible moisture or high humidity, especially during approach with low power settings. The FAA Carburetor Icing Probability Chart, given the atmospheric conditions at idle power, indicated a serious icing probability.