Explain why a helicopter with just one main rotor has a second smaller rotor mounted on a horizontal axis at t

Question

Explain why a helicopter with just one main rotor has a second smaller rotor mounted on a horizontal axis at the
rear as in Figure 10-43. Describe the resultant motion of the helicopter is this rear rotor fails during flight.

Answer 1

if it didn, have the other rotor it would spin the opposite way as the main rotor.

Answer 2

The smaller rotor counteracts the torque on the fuselage induced by the spinning main rotor.

If this rear rotor fails, the fuselage will spin in a direction opposite to that of the main rotor.

Answer 3

The tail rotor is to prevent the helicopter from rotating wildly out of control.

Without the tail rotor, the helicopter will spin in the direction of the main rotor's rotation and will crash.