What happened
During an aerial photographic survey flight, the pilot observed fuel leaking from around a fuel tank cap. Due to this mechanical issue, the pilot elected to divert to the nearest suitable airport, which was Soda Springs, Idaho.
Prior to landing, the pilot consulted two flight information publications, including the U.S. Government Airport/Facility Directory (A/FD), to gather necessary airport data. The pilot then commenced an approach to runway 16. A U.S. highway crosses the runway extended centerline approximately 50 feet north of the approach end, running perpendicular to the centerline. While the pilot reported being on a stabilized approach and following the glide path provided by the tri-color Visual Approach Slope Indicator (VASI), the aircraft collided with a truck on the highway.
The impact caused the loss of the aircraft's left main wheel. Despite the damage, the pilot successfully executed a go-around and proceeded to land at Pocatello, Idaho, without further incident. The occupants were not injured.
Findings
Following the accident, local airport authorities increased the glide path angle setting of the runway 16 VASI to provide greater clearance over the highway during final approach. It was noted that a previous aircraft/vehicle collision had occurred at this same location in 1978.