How far can downwash travel from the rotor diameter?

Downwash refers to the vertical airflow created by the rotation of a helicopter's rotor blades. It is an important concept in aviation, particularly in understanding how wake turbulence and the resulting airflow can impact other aircraft. The distance that downwash can travel from the rotor diameter is significant for maintaining safe distances between aircraft, especially in flight operations around helicopters.

The correct answer is that downwash can typically be observed to extend about three times the diameter of the rotor. This range accounts for the dispersion of the airflow as it moves away from the rotor blades, diminishing in intensity but still having potential effects on surrounding aircraft.

In terms of operational considerations, recognizing that downwash can impact other aircraft within this range helps pilots and air traffic controllers maintain safe separation and avoid potential conflicts. Understanding this concept is crucial for flight safety, particularly in scenarios where helicopters are operating in proximity to other aircraft.