Which of the following is a flight regime more susceptible to encountering ULY when turning from crosswind to downwind?

• A. Pilot Induced High Yaw Rates
• B. Left Sideward Flight
• C. Low Speed Left Downwind Turns
• D. Low Pedal Marding Maneuvers

Answer: (C)

Uncommanded lateral yaw tends to show up when yaw control authority is stressed by changing aerodynamic conditions, especially during airspeed transitions. Turning from a crosswind into a downwind changes how the rotor wash, tail rotor flow, and fuselage sideslip interact. At low airspeed, translational lift is reduced and the tail rotor’s effectiveness becomes more sensitive to the wind direction and rotor downwash. In a left-downwind turn, this combination amplifies small disturbances into noticeable yaw moments, so a pilot can experience yaw that isn’t fully commanded, i.e., ULY.

So, the regime where these factors line up most strongly is a low-speed left downwind turn, making it the most susceptible to encountering uncommanded yaw during that transition.