What minimum distance from the landing threshold is required for a second aircraft (CAT II) to land after the first aircraft (CAT I) has landed?

• A. 3000 feet
• B. 4500 feet
• C. 6000 feet
• D. 7500 feet

Answer: (B)

The minimum distance required for a second aircraft classified as Category II (CAT II) to land after the first aircraft classified as Category I (CAT I) has landed is 4,500 feet from the landing threshold. This distance is specified to ensure adequate separation and safety for the landing sequence of aircraft with different performance capabilities and operational criteria.

Category I aircraft typically rely on visual references during landing and may have different threshold crossing heights compared to Category II aircraft, which can utilize advanced instrument landing systems to land in lower visibility conditions. The additional distance ensures that the first aircraft has cleared the runway sufficiently and that the second aircraft has the appropriate landing configuration and space for its approach.

In contrast, lesser distances such as 3,000 feet would be insufficient to guarantee safe separation, as it might not allow the first aircraft enough time to exit the runway before the second aircraft begins its landing approach. Similarly, distances of 6,000 feet and 7,500 feet are greater than necessary in this context and could lead to inefficient use of the runway, potentially causing unnecessary delays. Thus, the 4,500 feet distance strikes a balance between safety and operational efficiency.