Accident Overview
A private pilot reported that during final approach to a private airport, the airplane developed a greater rate of descent than intended. The pilot stated he increased engine power slightly but refrained from adding more power because he did not want the airplane to "porpoise." He also chose to reduce the extension of the flaps.
Sequence of Events
While on approach, the pilot observed a vehicle approaching from his left on a public road situated near the approach end of the runway. He believed the airplane would clear the vehicle. Moments later, the airplane struck the vehicle, resulting in fatal injuries to both occupants. Postaccident inspection revealed no evidence of preimpact mechanical anomalies with the airplane.
Regulatory and Environmental Factors
The public road where the collision occurred was located 17.8 feet from the runway threshold. According to the FAA's publication FAA-H-8083-3, *The Airplane Flying Handbook*, if an undershoot condition develops during approach, power and pitch attitude should be increased to shallow the descent angle. The handbook advises against retracting the flaps, as doing so causes the airplane to sink more rapidly. To comply with the FAA's recommended minimum vertical obstruction clearance of 15 feet, the threshold would need to be displaced approximately 300 feet from the road.
The accident state is one of six nationwide that does not provide regulatory oversight or inspection of private airports.
Investigation Findings
No mechanical abnormalities were found in the airplane. The investigation focused on pilot actions during the approach and the proximity of the road to the runway threshold.