Loss of tail-rotor effectiveness

Loss of tail-rotor effectiveness (LTE)[1] occurs when the tail rotor of a helicopter is exposed to wind forces that prevent it from carrying out its function—that of cancelling the torque of the engine and transmission.

Environmental factors which can lead to LTE include higher operating-density altitudes or temperatures, and high winds.

A high gross weight can also create an LTE-conducive situation.

Causative wind-directions may include: Many factors affect the onset of LTE, but no matter which way it occurs, the clues are present: Recovery from an unexpected yaw movement is initiated by applying forward cyclic control to increase airspeed, and reducing power if at a safe altitude.

If these measures are not effective, an entry into an autorotation may be necessary, applying full opposite rudder until rotation stops.