The Witness Then Saw The Helicopter Strike The Powerlines And Observed An “Arc”

Location: Whiteside, TN Accident Number: ERA22FA383
Date & Time: August 23, 2022, 14:47 Local Registration: N770HP
Aircraft: Bell 206B Injuries: 2 Fatal
Flight Conducted Under: Public aircraft

On August 23, 2022, about 1447 central standard time, a Bell 206B helicopter, N770HP, was substantially damaged when it was involved in an accident near Whiteside, Tennessee. The pilot and the passenger/observer were fatally injured. The helicopter was operated as a public use aerial observation flight. The helicopter was operated by the Tennessee Department of Safety. The pilot was a sergeant with the Tennessee Highway Patrol, and the passenger/observer was a detective with the Marion County Sheriff’s Department.

According to the Tennessee Department of Safety, the pilot and the passenger/observer had been conducting a joint-agency marijuana eradication mission that day and stopped for lunch and fuel at the Marion County Airport (APT) in Jasper, Tennessee, at 1248. The pilot purchased 48 gallons of Jet A at 1251. After lunch, a call came in requesting back up for a pursuit that the Tennessee Department of Safety was engaged in. The pilot felt the pursuit would be over before they arrived to assist. Then a call came in about a missing person case that the passenger/observer was working and was not associated with the eradication mission. The pilot and passenger/observer departed at 1401 and flew to a set of coordinates of where the missing person was believed to be. The missing person was not located, and the helicopter returned to join the eradication efforts.

A witness was driving eastbound on Highway 24 toward Chattanooga, Tennessee, when he observed a “dark colored helicopter” headed westbound just north of the interstate. The witness was talking on the phone to his wife, and he told her how concerned he was that the helicopter was flying very low and near a set of powerlines. The helicopter did not appear to be in distress. The witness then saw the helicopter strike the powerlines and observed an “arc.”

The helicopter spun a few times and it appeared as if the pilot was trying to regain control. The witness said the helicopter descended out of view. At the same time, a broken section of a powerline cable fell on the highway in front of his vehicle. He was unable to stop in time and ran over the cable. The helicopter came to rest in heavily wooded and steep mountainous terrain on the west side of the powerlines. The nose of the helicopter was embedded in the ground on a ravine wall with the tail section pointed straight up in the air. There was no post-impact fire. The tail boom (minus the tail rotor) separated from the helicopter just aft of the horizontal stabilizer and was located downhill of the helicopter. This section of tail boom exhibited an impact mark consistent with contact of the main rotor blade. The tail rotor (minus one blade) was located approximately 100 ft east of where the helicopter came to rest and under the powerlines.

Damage to the tail rotor and tail rotor gearbox was consistent with impact damage. The other tail rotor blade was not located. The top portion of the vertical stabilizer had also separated from the helicopter and was found under the powerlines and adjacent to a set of train tracks located north of where the helicopter came to rest. The fractured area of the vertical stabilizer exhibited striated gouging marks consistent with contact with power lines.

One of the two main rotor blades remained partially attached and was fractured just outboard of the doubler. Examination of the blade revealed striated impact marks on the bottom of the blade about 2/3 outboard of the blade root. These striated marks were consistent with impact with the powerline. The other blade separated just outside its doubler and was found uphill of where the helicopter came to rest. The trailing edge tip of the blade exhibited arcing.

The wreckage and a handheld GPS unit were retained for further examination.

FMI: www.ntsb.gov