When following a Category B or D aircraft, how many minutes must an aircraft on an intersecting runway wait?

When managing aircraft separations on intersecting runways, a wait time of 2 minutes is required for an aircraft following a Category B or D aircraft. This rule is established to ensure safe separation due to the wake turbulence produced by larger aircraft, which can pose risks to smaller or lighter aircraft that follow them.

The 2-minute separation allows sufficient time for the wake turbulence to dissipate enough so that it does not affect the trailing aircraft. The decision is based on the types of aircraft involved, as different categories generate varying levels of turbulence. This time frame is a crucial component of air traffic control procedures, ensuring that the safety of all aircraft involved is maintained during operations at busy airports.

In contrast, the other options do not align with the established guidelines regarding wake turbulence separation. Shorter wait periods would not provide the necessary buffer, increasing the risk of wake turbulence-related incidents.