Loss of Tail Rotor Effectiveness (LTE): Uncommanded Right Yaw

Scenario & Physics Summary

Loss of tail rotor effectiveness is an uncommanded, rapid yaw toward the advancing blade that does not subside on its own. It is an aerodynamic interaction between the main rotor and tail rotor, not a mechanical failure (Helicopter Flying Handbook).

Interactive 3D Visual Plates & Scenario Media

Plate 1: Loss of Tail Rotor Effectiveness (LTE): Uncommanded Right Yaw

Plate 2: Loss of Tail Rotor Effectiveness (LTE): Uncommanded Right Yaw

Aerodynamic & Operational Physics

• LTE is a control margin deficiency in the tail rotor. It can affect all single-rotor helicopters that use a tail rotor.
• Contributing factors include main rotor downwash or vortices entering the tail rotor, turbulence, high power settings, slow forward airspeed where translational lift is changing, and the relative wind direction.
• The worst case is a relative wind within 15 degrees of the 10 o'clock position, which can blow main rotor vortices directly into the tail rotor.
• At high density altitude and high gross weight, hovering ceiling can be limited by tail rotor thrust and not only by power available.

FAA Exam Gotcha Alert

Exam Trap: LTE is not tail rotor failure. The recovery is full left pedal, forward cyclic to gain speed and, if altitude permits, a reduction in power, while a failed tail rotor is a different emergency.

Frequently Asked Questions & Exam Explanations