What happened
While conducting a banner towing operation at approximately 1,000 feet AGL, the pilot was entering the traffic pattern for an approach to runway 12. At an altitude of about 800 feet MSL, the engine began running rough, coughed, and subsequently lost power.
In response to the power loss, the pilot maneuvered the unspecified aircraft toward a nearby pasture. During the descent, the pilot executed the engine restart checklist and released the banner. Although the engine experienced several surges, it failed to regain consistent power.
The pilot performed a forced landing in an open field located roughly 3 miles from the airport. The aircraft touched down in a three-point attitude; however, during the subsequent landing roll, the airplane struck several small trees and crossed a fence line. There were no injuries reported.
The investigation
The investigation reviewed the engine's maintenance history, noting that the engine had accumulated a total of 2,659 hours, with 1,175 hours flown since its last overhaul. The investigation could not determine the specific reason for the loss of engine power.