Accident Overview
On December 1, 2024, at approximately 1438 central daylight time, an American Aviation AA-1B airplane, registration N6242L, sustained substantial damage during a forced landing near Brenham, Texas. The pilot and the passenger were not injured. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as a personal flight.
Events Leading to Forced Landing
The pilot reported a partial loss of engine power shortly after takeoff from runway 34 at Brenham Municipal Airport (11R). The loss of power occurred when the airplane was about 500 ft above the ground, crossing the departure end of the runway. The engine appeared to be running at idle power and was unable to sustain level flight. The pilot executed a forced landing in a grass field north of the airport.
Aircraft Damage
During the forced landing, the airplane's nose landing gear separated. The left wing leading edge was substantially damaged, exhibiting a large semicircular impact mark. Investigators noted that the damage likely resulted from a collision with the separated nose gear and/or with an anthill in the grass field. However, the leading edge showed no evidence of tire rubber transfer, scratching, or dirt or sand deposits.
Post-Accident Examination
Examination of the engine revealed no evidence of mechanical failure that would have prevented normal operation. A visual inspection of the engine's exterior found that all four engine cylinders had mud dauber nests within their respective cooling fins. Additionally, a mud dauber nest approximately 1.5 inches in diameter was discovered in the airbox, positioned between the air filter and the throat of the carburetor. Dirt of the same color as the nest was observed inside the carburetor throat and on the clean side of the air filter. The recovered nest displayed impressions consistent with the spacing of the wire coil that supports the flexible ducting associated with the carburetor heat system. The flexible ducting also contained various-sized fragments of mud dauber nest debris.
Maintenance History
The accident occurred about 4.7 hours since the last annual inspection, which was completed on November 17, 2024, during which the air filter was replaced. According to maintenance logbook documentation, the engine had accumulated 531.7 hours since the last major overhaul, completed on May 1, 1999.