Which statement about approach timing and rotor wash exposure is true?

Which statement about approach timing and rotor wash exposure is true?

• A. They are affected by both air speed and ground speed.
• B. They depend only on flight altitude.
• C. They depend only on payload weight.
• D. They are independent of speed.

Answer: (A)

Approach timing and rotor wash exposure depend on both air speed and ground speed. When the helicopter moves forward through the air, the rotor downwash tilts and spreads differently than in a hover, changing where and how strongly the wash reaches the ground. At the same time, how fast you traverse the area on the ground (ground speed) determines how long a person or object stays within that rotor wash. Higher airspeed changes the wash’s direction and footprint, while higher ground speed reduces exposure time, and slower ground speed increases it. Altitude or payload can influence the wash magnitude, but they don’t capture the combined effect of forward motion and time spent in the wash.

Approach timing and rotor wash exposure depend on both air speed and ground speed. When the helicopter moves forward through the air, the rotor downwash tilts and spreads differently than in a hover, changing where and how strongly the wash reaches the ground. At the same time, how fast you traverse the area on the ground (ground speed) determines how long a person or object stays within that rotor wash. Higher airspeed changes the wash’s direction and footprint, while higher ground speed reduces exposure time, and slower ground speed increases it. Altitude or payload can influence the wash magnitude, but they don’t capture the combined effect of forward motion and time spent in the wash.