How is dissymmetry of lift counteracted in the TH-73A tail rotor system?

• A. Delta hinge design
• B. Elastomeric bearings
• C. Balanced rotor blades when installed
• D. Retention bolts

Answer: (A)

The dissymmetry of lift in rotorcraft occurs when one side of the rotor experiences more lift than the other, which can lead to unwanted yaw or loss of control. In the TH-73A tail rotor system, the delta hinge design plays a crucial role in counteracting this effect. This design allows for independent movement of the rotor blades in response to varying aerodynamic forces, which helps maintain balance and stability during flight.

The delta hinge essentially provides freedom of movement for the rotor blades to flex and adjust their angle in a way that compensates for differences in lift across the rotor disc. This is particularly important during maneuvers where the aircraft may experience asymmetrical loading or when the tail rotor is operating in different phases of flight.

By allowing rotor blades to individually respond to changes in aerodynamic forces, the delta hinge design minimizes the effects of dissymmetry of lift, improving the control and performance of the helicopter. This design is integral to ensuring that the helicopter remains stable and responsive to pilot inputs.