What happened
An aircraft was flying at a low altitude along a roadway that passes through an east-west gap in a line of small mountains. During this flight, the aircraft struck power lines that were strung between towers located on ridges on either side of the road. The towers stood approximately 80 feet tall, with the ridges positioned about 380 feet above the roadway. The specific wire struck by the aircraft was not the uppermost wire and was situated roughly 243 feet above the road. Following the impact with the lines, the aircraft impacted the ground and came to rest on the highway.
The investigation
Investigators examined the wreckage and found that the fuel selector valve had been positioned for the left fuel tank. Both fuel tanks were found to be empty at the time of the accident. While the left fuel tank sustained damage, it did not rupture; however, the right fuel tank was ruptured. A smell of fuel was noted at the accident site. Based on fuel consumption calculations, the amount of fuel required for the flight should not have exceeded the capacity of the single selected tank. The investigation found no preimpact anomalies regarding the engine, systems, or the aircraft itself.
Findings
- The power lines were not marked with high visibility devices.
- The transmission towers were not lighted.