In a T/R Quad Fail caution, with loss of control, which component positions the tail rotor servo linkage?

In a T/R Quad Fail caution, with loss of control, which component positions the tail rotor servo linkage?

• A. Tail rotor servo valve
• B. Hydraulic pump
• C. Centering spring
• D. Servo linkage

Answer: (C)

When hydraulic power to the tail rotor system is lost, the tail rotor servo valve can no longer command a position. The centering spring is what sets the servo linkage to the neutral (centered) position in this scenario. It provides the mechanical return force that keeps the tail rotor pitch near mid-position, reducing uncommanded yaw and making the aircraft safer to control with no hydraulic actuation. The hydraulic pump isn’t delivering pressure, and the servo valve isn’t actively moving the linkage, so the centering spring is the mechanism that positions it.

When hydraulic power to the tail rotor system is lost, the tail rotor servo valve can no longer command a position. The centering spring is what sets the servo linkage to the neutral (centered) position in this scenario. It provides the mechanical return force that keeps the tail rotor pitch near mid-position, reducing uncommanded yaw and making the aircraft safer to control with no hydraulic actuation. The hydraulic pump isn’t delivering pressure, and the servo valve isn’t actively moving the linkage, so the centering spring is the mechanism that positions it.