A B744 is executing a low approach on Runway 18, and a King Air is ready for takeoff on Runway 36. What is the minimum separation required to clear the King Air for takeoff?

• A. 1 minute
• B. 2 minutes
• C. 3 minutes
• D. 4 minutes

Answer: (C)

In this scenario, the minimum separation required for the King Air to be cleared for takeoff while the B744 is executing a low approach on Runway 18 is determined by the type of aircraft involved and their operational characteristics.

A B744, being a large aircraft, creates a significant wake turbulence, which is a crucial factor in determining separation time. When a large aircraft, such as a B744, is performing a low approach, it can generate wake vortices that could potentially create hazardous conditions for smaller aircraft, like the King Air during takeoff.

To ensure safe operations, especially considering the size difference and the potential for wake turbulence, the Federal Aviation Administration (FAA) recommends a minimum separation time of 3 minutes between a large aircraft on approach and a smaller aircraft taking off from a runway that is parallel, but not intersecting, with the approach path of the larger aircraft. This time allows for the dissipation of the vortices and reduces the risk of wake turbulence encountering the smaller aircraft.

Therefore, the correct answer is 3 minutes, as this timeframe provides a sufficient buffer to maintain safety while enabling the King Air to take off without undue risk.