When must ZAE ensure that aircraft land at KHEZ or KMCB cross the ZAE/ZHU boundary?

The requirement for ensuring that aircraft land at KHEZ or KMCB when crossing the ZAE/ZHU boundary occurs at or below 12,000 feet. This altitude is significant as it is aligned with the way air traffic control manages airspace and coordinates safe entry and exit points between different control areas.

At this altitude, the air traffic control measures are in place to help maintain the safety and efficiency of aircraft operations, especially when transitioning between different sectors of responsibility. It allows controllers to ensure that aircraft are properly sequenced and that any handoffs between controllers are managed effectively as they prepare to land.

Other altitude options would either allow for a wider margin of operation or may not adhere to specific operational agreements between adjacent air traffic control sectors. Setting the threshold at or below 12,000 feet is a practical strategy for busy airspace, helping to prevent congestion and ensuring that all arriving flights maintain a safe distance from each other as they approach their destination airports.