SEA07FA119 · Cessna 182C

After preflighting the airplane, adding fuel and checking the oil, the pilot radioed that he was taxiing to runway 32. Witnesses subsequently observed the airplane takeoff on runway 32, make a 180-degree turn toward the south, and then fly downwind and parallel to the runway at an altitude of between 300 and 500 feet above ground level. At approximately the end of the runway the airplane was observed making a left turn onto base leg for runway 32, followed by a steep turn to final before nosing into the ground and bursting into flames. The initial onsite examination of the airplane revealed that the engine's oil cap was not attached to the oil filler tube. A further examination revealed damage to the oil filler tube and no damage to the oil filler cap, which would indicate that the cap was not in place at the time of impact. A section of the right aileron and pieces of the airplane's windshield were examined for oil residue; no oil residue was detected on those parts. Weight and balance information for the flight indicated that the airplane was approximately 165 pounds over its maximum gross takeoff weight at the time of the accident. As a result of the engine's oil filler cap not being secured to the oil filler tube, it is reasonable to expect that an amount of oil would have escaped the engine and blown back over the pilot's windscreen, thereby obstructing his vision. The obstructed windscreen, coupled with the airplane's gross takeoff weight being exceeded, 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.

Verbatim NTSB analysis and probable cause from the NTSB dataset