Bender Joseph KIT ROTOWAY N164JB

Summary

On 30 April 2017 at about 23:15 local time, a Bender Joseph KIT ROTOWAY registered N164JB was involved in an accident near Wheatland, Wyoming, United States. One person was on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

30 April 2017 at 23:15

Classification

Accident

Location

Wheatland, Wyoming, United States

Coordinates

42.0775, -105.0578

Aircraft

Bender Joseph KIT ROTOWAY

Registration

N164JB

Category

Helicopter

Year built

2004

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Wheatland → Wheatland

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

GAA17CA251

Nobody was injured.

The pilot's decision to operate the helicopter in gusting wind and high-density altitude conditions and his positioning of the helicopter such that it resulted in a right quartering tailwind, which resulted in a loss of helicopter control due to a loss of tail rotor effectiveness.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The pilot of the experimental amateur-built helicopter, which had a clockwise rotating main rotor blade, reported that he took off from private property with a right crosswind. He added that, when the helicopter reached 20 to 30 knots, about 50 ft above the ground, he turned southwest, which resulted in a right quartering tailwind. He further added that, as he made the turn, he applied right antitorque pedal, but "nothing was there." The pilot reported that he subsequently decided to "set it down" in a field ahead and that, about 3 to 5 ft above the ground, the "tail started to come around counter-clockwise." During the touchdown, the right skid caught on a hidden car muffler, and the helicopter rolled onto its right side and impacted terrain. During a postaccident interview, the pilot reported that he "lost tail rotor effectiveness," and he encountered "too much wind for this aircraft [helicopter]." The main rotor and tailboom sustained substantial damage. The pilot reported that there were no preaccident mechanical malfunctions or failures with the helicopter that would have precluded normal operation. The pilot reported that the wind was from the north and about 15 knots. The nearest automated weather observation station (AWOS), 41 nautical miles (nm) from the accident site, recorded that, about the time of the accident, the wind was from 350° at 14 knots, gusting to 26 knots. About 20 minutes before the accident, the AWOS recorded a peak wind from 340° at 30 knots. The density altitude at the AWOS location was 5,332 ft. The Federal Aviation Administration Helicopter Flying Handbook stated, in part: "Loss of tail rotor effectiveness (LTE) or an unanticipated yaw is defined as an uncommanded, rapid yaw towards the advancing blade which does not subside of its own accord. It can result in the loss of the aircraft if left unchecked." The handbook further stated, in part: "At higher altitudes where the air is thinner, tail rotor thrust and efficiency are reduced. Because of the high density altitude, powerplants may be much slower to respond to power changes. When operating at high altitudes and high gross weights, especially while hovering, the tail rotor thrust may not be sufficient to maintain directional control, and LTE can occur." It is likely that the high-density altitude and the pilot's positioning of the helicopter such that it resulted in a right quartering tailwind reduced the tail rotor effectiveness of the helicopter and contributed to the pilot's inability to maintain helicopter control during the hover to landing.

Quoted verbatim from the NTSB record.