History of Flight
On August 1, 2011, at about 1818 eastern daylight time, a Bell 206 L4 helicopter, registration N484AE, operated by Air Evac EMS, Inc., sustained minor damage in a wire strike during takeoff from a farm field in Reliance, Tennessee. The helicopter was conducting a medical evacuation flight under 14 CFR Part 135, destined for Erlanger Medical Center Heliport (0TN8) in Chattanooga, Tennessee. The pilot, two crewmembers, and one patient were not injured. Visual meteorological conditions prevailed, and a company flight plan was filed.
The pilot reported that the landing zone was a large field, chosen after a high and low reconnaissance of the area. The local fire department established a landing zone command, which briefed the crew on obstacles including wires along the road north of the field and large hay rolls. After calculating weight and power, the pilot decided on an airspeed-over-altitude takeoff with a westerly departure path, as the field offered a long, open area with down-sloping terrain. The departure path was approved by the landing zone commander via a firefighter.
During takeoff, when the helicopter reached 50 feet and 40 knots, the pilot adjusted for a 60-knot climb. Moments later, he heard a loud "thud" and saw scuff marks on the windscreen, indicating a wire strike. He declared an emergency and completed a precautionary landing back to the field. Written statements from both crewmembers corroborated the pilot's account.
Aircraft and Pilot Information
The pilot held a commercial pilot certificate with rotorcraft-helicopter and instrument-helicopter ratings, reporting 2,173 total flight hours, including 116 hours in the accident helicopter make and model. His most recent FAA second-class medical certificate was issued on June 1, 2011. The helicopter, manufactured in 2010, had its most recent inspection under the Approved Aircraft Inspection Program on July 27, 2011, at 564 total aircraft hours.
Meteorological Information
At 1853, weather at Lovell Field in Chattanooga, approximately xx miles from the site, reported few clouds at 6,500 feet, visibility 10 miles, temperature 36°C, dew point 15°C, altimeter 29.93 inches of mercury, and wind from 120° at 6 knots. Calculated density altitude was 3,318 feet. The sun's azimuth was 273° east of north at an altitude of 28° above the horizon.
Investigation
An FAA aviation safety inspector examined the site on August 2, 2011. Damage to the helicopter was limited to the windscreen; scratches in the paint and marks on the upper and lower Wire Strike Protection System were consistent with a wire strike. The inspector observed a three-strand group of wires crossing the west side of the field perpendicular to the takeoff path. From the departure point, the wires were superimposed against a background of dense woods and were not associated with any visible poles, towers, or transformers.