Bell 206 N519EH

Summary

On 2 February 2017 at about 00:30 local time, a Bell 206 registered N519EH was involved in an accident near Carson City, Nevada, United States. 2 people were on board and 2 had minor injuries. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

2 February 2017 at 00:30

Classification

Accident

Location

Carson City, Nevada, United States

Nearest airport

Carson (CXP)

Coordinates

39.1922, -119.7325

Aircraft

Bell 206

Registration

N519EH

Category

Helicopter

Year built

1980

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Instructional

Phase of flight

Not recorded

Route

Carson City → Carson City

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

GAA17CA132

2 people had minor injuries.

The pilot-in-command’s delayed remedial action to arrest the right yaw after the bounced landing while operating in a flight regime conducive to the loss of tail rotor effectiveness, which resulted in a roll-over.

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

Read the full NTSB narrative

The flight instructor on the controls of the high skid-equipped-landing-gear helicopter reported that he was the pilot-in-command (PIC). The PIC reported that he and another flight instructor were performing simulated emergency procedures during the flight. He reported that he attempted to demonstrate a simulated fixed-pitch (right stuck antitorque pedal) emergency procedure. He reported that, during the maneuver, the nose of the helicopter was about 40° nose right of centerline. He reduced the throttle, and the nose corrected to about 20° nose right of centerline. The helicopter touched down on taxiway delta with minimal forward airspeed, and it then bounced about 5 ft above the ground and yawed right about 1 3/4 turns. The helicopter touched down a second time about 65 ft south of the taxiway centerline and rolled onto its left side. The helicopter sustained substantial damage to the firewall, main rotor drive system, and tail rotor drive system. A METAR at the time of the accident reported that the wind was from 110° at 08 kts. The flight instructor seated in the right seat reported that the wind at the time of the accident was from 090° at 08 kts. When the PIC was asked by the National Transportation Safety Board investigator-in-charge if he placed the collective in the full-down position after touchdown or if he increased the collective after the initial touchdown, he responded that he could not remember. When asked if he applied full left pedal to combat the right yaw, he said that he did not because the event happened quickly. According to the Federal Aviation Administration Helicopter Flying Handbook (FAA-8083-21A), the Helicopter Instructor's Flying Handbook (FAA-8083-4), and Advisory Circular (AC) 90-95 "Unanticipated Rapid Right Yaw in Helicopters," the loss of tail rotor effectiveness is a critical, low-speed aerodynamic flight characteristic that can result in an uncommanded rapid yaw rate that does not subside of its own accord and, if not corrected, can result in the loss of aircraft control. AC 90-95, Section 7.d.3. (page 7), defines flight characteristics and wind azimuths and states that the tail rotor vortex ring state occurs when the wind is from 210° to 330°. 1. Winds within this region will result in the development of the vortex ring state of the tail rotor. AC 90-95, Section 10, "Recommended Recovery Techniques," (page 8), states: a. If a sudden unanticipated right yaw occurs, the pilot should perform the following: (1) Apply full left pedal. Simultaneously, move cyclic forward to increase speed. If altitude permits, reduce power. (2) As recovery is effected, adjust controls for normal forward flight. b. Collective pitch reduction will aid in arresting the yaw rate but may cause an increase in the rate of descent. Any large, rapid increase in collective to prevent ground or obstacle contact may further increase the yaw rate and decrease rotor rpm. The pilot reported that there were no preaccident mechanical malfunctions or failures with the helicopter that would have precluded normal operation.

Quoted verbatim from the NTSB record.