If flight paths will cross, how many minutes must a departure behind a Category B or D departure on an intersecting runway wait?

When a flight is scheduled to depart behind a Category B or D aircraft on an intersecting runway, specific separation criteria must be adhered to in order to ensure safety during takeoff and minimize the risk of wake turbulence. In this case, a departure is required to wait for a minimum of two minutes after the preceding Category B or D departure.

The significance of the two-minute wait is rooted in the need to allow sufficient time for the larger aircraft to gain altitude and distance, which diminishes the effects of wake turbulence. This is particularly critical given that Category B and D aircraft typically have specific characteristics that can generate significant wake turbulence, making it essential to create adequate spacing before a subsequent departure occurs.

This regulation not only enhances safety but also helps maintain efficient operations on the runway. Adhering to this guideline is crucial for air traffic controllers when managing the flow of departures near intersecting runways.