On September 22, 1999, a Bell 206L-1 (registration N17SP) was involved in an aviation accident near Randolph, NY. Investigators recorded the probable cause as: The pilot's failure to see and avoid utility wires while flying at low altitude in a valley environment toward the sun. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A helicopter conducting a drug eradication mission struck utility wires in a valley while flying toward the sun at low altitude, resulting in an accident.
What happened
The pilot was operating a helicopter on a mission to eradicate illegal drugs. During the flight, the aircraft was navigating through a valley environment. The pilot directed the aircraft toward the position of the sun, which likely contributed to visual challenges. At the time of the incident, the helicopter was flying at an altitude of approximately 200 feet above ground level.
While maintaining this low altitude, the helicopter collided with utility wires. These wires were suspended between towers that were situated below the local tree line. The obstruction was not immediately obvious due to the terrain and lighting conditions.
The investigation
An examination of the relevant aeronautical charts revealed that the location of the utility wires was accurately depicted on the current Detroit Sectional Aeronautical Chart. Despite being charted, the wires presented a hazard during the specific flight conditions encountered by the pilot.
Probable cause
The pilot's failure to see and avoid utility wires while flying at low altitude in a valley environment toward the sun.