What happened
Shortly after takeoff, a Cessna (type not specified) began a right turn to return to the airport. During the climb, which reached between 100 and 200 feet above ground level, the pilot transmitted via radio that a return was necessary because the engine's oil filler cap had been left off. This error caused a layer of oil to coat the windshield, obstructing the pilot's vision.
The aircraft subsequently descended into terrain approximately 300 yards south of the departure end of the runway. At the time of impact, the airplane was at a wings-level attitude with a 20-degree nose-down position. The pilot reported no injuries and stated there were no mechanical malfunctions or failures present prior to the impact.
The investigation
First responders at the scene observed that the aircraft's windshield was coated in a layer of oil, consistent with the pilot's report. The pilot noted that the incident could have been avoided had the oil cap been properly replaced during the preflight inspection.