17 / 20

The flexible couplings are primarily utilised in the drive system of a helicopter to:

I. Facilitate the assembly and disassembly of the shafts.
II. Alleviate any angular deviation of the shafts.

Which of these statements are correct or incorrect?

  • A
    I is correct; II is correct
  • B
    I is correct; II is incorrect
  • C
    I is incorrect; II is incorrect
  • D
    I is incorrect; II is correct

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.

Therefore, flexible couplings are mainly used in order to alleviate any angular deviation of the shafts and the correct answer is "I is Incorrect, II is Correct".

Your Notes (not visible to others)

This question has appeared on the real examination, you can find the related countries below.