Bell 206 N484AE incident near Relience, Tennessee

Probable cause

Inadvertent contact with wires due to the lack of visual cues regarding their presence and the low angle of the sun, which was directly in the takeoff path.

NTSB analysis

Before landing, the pilot performed a high and low reconnaissance of the area and received a briefing of the obstacles by the landing zone. The crew was advised of wires along the road north of the field and large rolls of hay spaced intermittently across the field. The pilot then landed the helicopter in a field and picked up a patient who had been involved in a motor vehicle accident. Given the weight of the helicopter and power available, the pilot elected to perform an airspeed-over-altitude takeoff on a westerly departure path along the long axis of the landing zone. The departure path was signaled to the landing zone commander, who issued an approval for the takeoff. During the initial takeoff climb, the helicopter struck wires and returned to the field for landing. After the incident, a closer inspection of the takeoff path revealed that a three-strand group of wires crossed the west side of the field perpendicular to the takeoff path. When viewed from the point of departure, the wires appeared to emanate from the thick, tall tree lines that bordered both sides of the landing zone, and were superimposed against a background of dense woods. There were no additional visual cues (poles, towers, or transformers) available that could be associated with the wires. Additionally, at the time of the accident, the sun was directly in the takeoff path and 30 degrees above the horizon. The bright sunlight and glare conditions likely reduced the ability of ground crew and the flight crew to discern wire obstacles.

Text from the NTSB. Open the NTSB docket for ERA11IA436 for the full record.