What happens in Main Rotor Disk Vortex Interference?

What happens in Main Rotor Disk Vortex Interference?

• A. Directed onto the tail rotor
• B. Increases tail rotor lift
• C. Reduces tail rotor drag
• D. Causes immediate tail rotor failure

Answer: (A)

The main rotor creates a strong wake and downwash as it spins. In certain flight conditions, this wake is carried downstream toward the tail, so the tail rotor ends up operating in disturbed air. This is the essence of main rotor disk vortex interference: the main rotor's flow is directed onto the tail rotor. This interaction changes the inflow seen by the tail rotor and can reduce its effectiveness, leading to yaw instability or fluctuations rather than improving thrust or causing a sudden failure.

The main rotor creates a strong wake and downwash as it spins. In certain flight conditions, this wake is carried downstream toward the tail, so the tail rotor ends up operating in disturbed air. This is the essence of main rotor disk vortex interference: the main rotor's flow is directed onto the tail rotor. This interaction changes the inflow seen by the tail rotor and can reduce its effectiveness, leading to yaw instability or fluctuations rather than improving thrust or causing a sudden failure.