Refer to figures.
Tail rotor flexible couplings are mechanical components designed to connect short drive shafts across the tail rotor drive shaft running at very high speeds, which transmit drive and power from the Main Rotor to Tail Rotor Gearbox.

These couplings are specifically designed to:

• absorb the angular differences that arise from the bending of the tail;
• damp out vibration as they accellerate or decelerate;
• allow for flexing of the airframe in flight and changes in length from thermal expansion and contraction;
• ensure smooth and efficient power transmission while minimizing stress.
• allow for minor misalignments, ensuring smooth operation and preventing issues such as snatch engagement, which can cause damage to the driveshaft.