The T/R Quad Fail caution indicates loss of control due to which event?

The T/R Quad Fail caution indicates loss of control due to which event?

• A. Both tail rotor cables have failed
• B. Tail rotor hydraulic line ruptured
• C. Tail rotor pitch link worn
• D. Tail rotor speed sensor failure

Answer: (A)

The important idea is tail rotor drive redundancy. In the UH-60, the tail rotor is powered through multiple drive cables to keep the yaw control active even if some components fail. When the T/R Quad Fail caution appears, it means the tail rotor drive has been lost because both tail rotor drive cables have failed, so the tail rotor can no longer generate thrust to counteract the main rotor torque. With no tail rotor thrust, the helicopter will yaw uncontrollably and can quickly lose directional control. Other failure modes would affect different aspects: a ruptured hydraulic line would degrade tail rotor pitch control rather than remove drive entirely; a worn tail rotor pitch link would make pitch control unreliable; a failed tail rotor speed sensor would disrupt the commanded tail rotor response but not necessarily wipe out drive. The key point is the complete loss of tail rotor drive from failures in both drive cables, leading to loss of control.

The important idea is tail rotor drive redundancy. In the UH-60, the tail rotor is powered through multiple drive cables to keep the yaw control active even if some components fail. When the T/R Quad Fail caution appears, it means the tail rotor drive has been lost because both tail rotor drive cables have failed, so the tail rotor can no longer generate thrust to counteract the main rotor torque. With no tail rotor thrust, the helicopter will yaw uncontrollably and can quickly lose directional control.

Other failure modes would affect different aspects: a ruptured hydraulic line would degrade tail rotor pitch control rather than remove drive entirely; a worn tail rotor pitch link would make pitch control unreliable; a failed tail rotor speed sensor would disrupt the commanded tail rotor response but not necessarily wipe out drive. The key point is the complete loss of tail rotor drive from failures in both drive cables, leading to loss of control.