IAD00LA015

The pilot was conducting an aerial observation of powerlines with three passengers onboard. The pilot stated he was heading westbound checking a cross arm at a slow hover. He then began to accelerate and turned east about 100 feet above the ground when a gust of wind pushed against the helicopter and the helicopter began to rotate to the right. The pilot attempted to accelerate into the wind to no avail and the aircraft 'corkscrewed' down into the ground. On the ground, the helicopter rolled on to its right side. Winds were reported out of the west at 280 degrees at 16 knots gusting to 22 knots 15 miles east of the accident site. No pre-impact deficiencies were reported with the engine or airframe.

On January 5, 2000, about 1408 eastern standard time, a Bell 206A, N206GR, was substantially damaged when it collided with trees and terrain during an uncontrolled descent near Brutus, NY. A company flight plan was filed for the flight that originated at Oneida County Airport (UCA), Utica, NY. The commercial pilot and three passengers were not injured. Visual meteorological conditions prevailed for the flight conducted under 14 CFR part 91.

At the scene, the pilot reported to the New York State police, that the purpose of the flight was to check powerlines. According to the New York State Trooper's report:

"The chopper was checking lines along route 31 in the town of Brutus traveling about 40 mph east bound at 100 feet from the ground and 50 feet above the powerlines and to the south of them. Suddenly the chopper got caught in a gust of wind and lost tail rotor effectiveness and started spinning like a top. Pilot attempted to recover and accelerate into the wind to no avail, and started to nose dive. Pilot looked for the safest spot to land and cut the power descending into the trees, 'corkscrewing' down to the ground."

In a written statement, the pilot said:

"All operations that day were normal without any adverse wind effects. Returned to one structure to check cross arm and was heading west. At slow hover 10 miles per hour accelerated to 50-60 miles per hour. Turned east along lines and was indicating 40-50 miles per hour at approximately 100 feet above ground level when helicopter suddenly went into a rapid right rotation. Reduced collective to try and control rotation. Went through 360 degrees and was descending into trees. Rolled throttle to idle and applied collective to cushion landing. After touchdown aircraft rolled on right side."

According to the passenger seated behind the pilot, "We were heading east when the helicopter started to turn to the right. I know we spun a lot, but I haven't any idea how many times. We hit hard and rolled on to our right side."

A second passenger said, "As we were flying parallel along a transmission line, a gust of wind pushed against the helicopter causing us to go into a slow turn/spin. The pilot started to control the aircraft when it seemed like another gust of wind came up and pushed us harder into a faster spin."

A third passenger said, "While watching the pole structures the helicopter began to make a right hand turn for apparently no reason. The pilot was trying to bring the helicopter back around the way we were heading to begin with, when it did another 360 degree turn. After a few more 360 degree turns, I remember hearing the engine shut down or slow down and the pilot tried to guide us to the ground."

The pilot reported there were no mechanical deficiencies with the helicopter. He reported a total of 2,844 flight hours with 2,211 in rotorcraft with 216 in make and model.

Winds at Syracuse, New York, 15 miles east of Brutus were from 280 degrees at 16 knots gusting to 22 knots.

Maximum gross weight of the helicopter was 3200 pounds. According to information provided by the Federal Aviation Administration (FAA), the estimated gross weight of the helicopter at the time of the accident was 2,785 pounds.

According to FAA Advisory Circular (AC) 90-95, it states that "Any maneuver which requires the pilot to operate in a high power, low airspeed environment with a left crosswind or tailwind creates an environment where unanticipated right yaw may occur." The AC also advised of greater susceptibility for loss of tailrotor effectiveness (LTE) in right turns and the phenomena may occur in varying degrees in all single main rotor helicopters at airspeeds less than 30 knots.