Pilot Debrief

BELL 206 near Relience, TN — 2011-08-01

Final reportERA11IA436
Sign in to save
Date
2011-08-01
Location
Relience, TN, USA
Aircraft
BELL 206
Registration
N484AE
Category
Helicopter
Highest injury
None
Fatalities
0
Phase of flight
Takeoff roll

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 narrative

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.

Analysis

Primary failure mode
Human factors
First missed decision gate
Pilot could have chosen a different departure path to avoid wires.

NTSB coding

  • Controlled flight into terr/obj (CFIT) · Initial climb

Evidence available

  • Photos
  • 8 docket documents
View NTSB final reportView NTSB docket

Docket documents8

Related mishaps