CHI95LA335

The pilot said he was demonstrating maneuvers over tall grass near a hill. A tail wind of five to ten knots was present. He thought the helicopter's tail stinger struck the hill while operating at 110% torque. The pilot said he over controlled the collective when he reduced torque. The pilot said the helicopter descended rapidly after he reduced the torque, striking the ground and rolling onto its left side. During training, the manufacturer's instructor pilots had strongly emphasized to the pilot the importance of staying below maximum torque. The pilot stated this strong emphasis resulted in his reducing the collective rapidly and ultimately the hard collision with terrain.

On September 28, 1995, at 1400 eastern daylight time (edt), a Bell 206B, N28SJ, piloted by a private pilot was substantially damaged while maneuvering at Eagle Creek Airpark, Indianapolis, Indiana.The personal 14 CFR part 91 flight was not operating on a flight plan. Visual meteorological conditions existed at the time of the accident. The pilot reported no injuries, the passenger reported minor injuries. The flight departed Indianapolis, Indiana at 1350 edt.

According to the pilot's written statement he was demonstrating maneuvers to his passenger. The helicopter was operating over tall grass, with a tail wind of five to ten knots. The helicopter was heading north according to the pilot. A hill that sloped from the east down to the west was on the helicopter's right side. While stopping forward motion, the pilot thought that he struck the helicopter's tail stinger on the slope and then noticed a vibration. Checking the engine instruments, the pilot said the engine torque gauge showed 110%. The pilot said he over controlled when reducing torque. The aircraft struck the ground hard causing the helicopter to roll onto its left side.

During a telephone interview with the pilot he said that he was a low time pilot. He also said that during transitional training taken at the helicopter manufacturer's facilities the instructor pilots had often emphasized the importance of staying below maximum torque. The pilot felt this emphasis caused him to over control the helicopter.

Copies of the pilots operating handbook (POH) were obtained from both the pilot and the aircraft manufacturer. The POH specified a transient torque limit of five seconds at 110%. Hand written notes in the students POH included the cost for a hot section inspection or turbine wheel replacement.

During a telephone conversation with the manufacturer's instructor pilot, he said the instructors do emphasize the problems associated with an over torque condition. He said that during training students are shown a transmission sun gear that has been damaged due to an over torque condition.

The helicopters main rotor blades had separated from its mast. The transmission deck was collapsed and the tail boom was bent. The pilot reported the tail rotor and skids were "...clipped..." and the plexiglass windows were shattered.