What is the effect of vortex ring state on the helicopter's vertical rate of descent?

• A. Increases climb rate
• B. Decreases climb rate (increases descent rate)
• C. No change
• D. Increases airspeed

Answer: (B)

Vortex ring state happens when the helicopter descends into its own downwash, so the rotor is surrounded by a toroidal vortex of rotating air. That recirculated flow disrupts the rotor’s ability to produce lift, effectively starving the rotor of clean airflow. With lift reduced while gravity continues to pull the aircraft downward, the helicopter sinks faster and can’t climb as well. So the vertical rate of descent increases and the climb rate decreases. It’s not a change that would increase airspeed or keep the same lift; the condition directly reduces rotor thrust. Recovery involves re-energizing the rotor flow, typically by gaining forward airspeed to exit the recirculating downwash and then increasing collective only after the rotor is again clean.