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.