What minimum longitudinal separation is required in minutes when applying the 44-knot rule?

The 44-knot rule is a guideline used in air traffic control for ensuring safe separation between aircraft that are operating at different speeds, particularly when one aircraft is overtaking another. When one aircraft is slower than 44 knots than the aircraft ahead, it is required to maintain a minimum longitudinal separation to prevent any potential conflicts or collisions.

In this context, the correct answer indicates that a minimum of 3 minutes of longitudinal separation is needed when applying the 44-knot rule. This time frame allows sufficient distance between two aircraft, taking into account their speeds and the variability in their flight paths. The 3-minute separation ensures that even if the overtaking aircraft is significantly faster, it can safely pass without infringing on the airspace occupied by the slower aircraft ahead.

Understanding this rule is essential for managing traffic efficiently, particularly in busy airspace, and allows air traffic controllers to maintain a high safety standard while handling the complexities of aircraft speeds and trajectories.