The Accident
After completing a preflight inspection, adding fuel, and checking the oil, the pilot radioed intentions to taxi to runway 32. Witnesses observed the airplane take off from runway 32, execute a 180-degree turn to the south, and fly downwind parallel to the runway at an altitude between 300 and 500 feet above ground level. Near the end of the runway, the airplane turned left onto the base leg for runway 32, followed by a steep turn to final. During this maneuver, the airplane nosed into the ground and burst into flames.
Examination Findings
An initial onsite examination revealed that the engine's oil filler cap was not attached to the oil filler tube. Further examination showed damage to the oil filler tube but no damage to the oil filler cap, indicating the cap was not in place at the time of impact. A section of the right aileron and pieces of the windshield were tested for oil residue; none was detected.
Weight and balance calculations for the flight indicated that the airplane was approximately 165 pounds over its maximum gross takeoff weight at the time of the accident.
Analysis of Factors
Given the unsecured oil filler cap, it is reasonable to expect that an amount of oil would have escaped from the engine and blown back over the pilot's windscreen, obstructing the pilot's vision. The obstructed windscreen, combined with the airplane exceeding its maximum gross takeoff weight, would most probably explain the pilot's loss of control while attempting to return to the runway. No pre-impact anomalies were noted with either the airframe or the engine.