Pilot Debrief

BELL 206 near Minden, NV — 2017-08-20

Final reportGAA17CA495
Sign in to save
Date
2017-08-20
Location
Minden, NV, USA
Airport
MEV
Aircraft
BELL 206
Registration
N6259C
Category
Helicopter
Highest injury
None
Fatalities
0
Phase of flight
Landing

Probable cause

The pilot’s failure to maintain helicopter control during landing due to a loss of tail rotor effectiveness.

NTSB narrative

The pilot of the helicopter reported that, during landing, the helicopter "encountered LTE [loss of tail rotor effectiveness]." He added that he maneuvered the helicopter to an open field adjacent to the intended helipad and that the tail rotor impacted a barbed wire fence. The helicopter sustained substantial damage to the empennage. The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation. The Federal Aviation Administration's Helicopter Flying Handbook, FAA-H-8083-21A, contained a section titled "Loss of Tail Rotor Effectiveness (LTE)," which stated: 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. It is very important for pilots to understand that LTE is caused by an aerodynamic interaction between the main rotor and tail rotor and not caused from a mechanical failure. Some helicopter types are more likely to encounter LTE due to the normal certification thrust produced by having a tail rotor that, although meeting certification standards, is not always able to produce the additional thrust demanded by the pilot.

Analysis

Primary failure mode
Loss of control
First missed decision gate
Pilot could have chosen a different landing approach to avoid LTE.

NTSB coding

Evidence available

  • Photos
  • 2 docket documents
View NTSB final reportView NTSB docket

Docket documents2

Related mishaps