Which is a recommended wake vortex avoidance procedure?

Flying at or above a heavy aircraft's flight path is a recommended wake vortex avoidance procedure because it helps mitigate the effects of wake turbulence generated by heavier aircraft. Wake turbulence occurs when a large aircraft generates eddies and vortices as it moves through the air, particularly during takeoff and landing. These vortices descend and spread out behind the aircraft, creating a potentially hazardous situation for trailing or crossing aircraft.

By maintaining altitude above the flight path of a heavy aircraft, pilots can avoid the turbulence that typically sinks below the aircraft's flight path. This is especially important in scenarios such as landing approaches and takeoff sequences, where aircraft are closer together in terms of horizontal proximity and where the effects of wake turbulence can be especially pronounced.

The other choices suggest procedures that do not effectively mitigate the risks associated with wake turbulence. For example, landing soon after a heavy aircraft can place another aircraft in the path of its wake turbulence. Ensuring minimal distance behind heavy aircraft is also not sufficient as it does not prevent the influence of wake turbulence. Rotating before the heavy aircraft has left the ground may lead to challenges both in terms of performance and potential wake encounters, as the trailing aircraft may still be affected by the turbulence before the leading aircraft fully departs the runway