Accident Description
The helicopter was destroyed following a loss of tail rotor effectiveness while landing. After losing tail rotor effectiveness, the pilot was able to land the helicopter in a field amongst pine trees. The main rotor struck the trees and the helicopter rolled over on its right side. A fire erupted and the helicopter was consumed.
Pilot Account
The pilot stated that, as he approached the landing area, the helicopter was about 250 pounds below maximum gross weight of 3,200 pounds. He decided to abort the landing and began a power pull to 100 percent torque and a transition to forward flight. The helicopter immediately began a rapidly accelerating yaw to the right. The pilot believed he still had a functioning tail rotor, but that it may have entered a 'loss of tail rotor effectiveness' state and need only be regained. He also stated that the 'low rotor RPM' warning light and horn began to come on with each pull of the collective.
Advisory Circular Reference
A Federal Aviation Advisory Circular states that a loss of translational lift results in increased power demand and additional anti-torque requirements. The AC also states that when operating at or near maximum power, this increased power demand could result in a decrease in rotor rpm. Any reduction in the translational lift will result in an increase in power demand and anti-torque requirements.