What does the [25] indicate in the airspace surrounding Naval Air Station Kingsville (NQI)?

The notation [25] in the airspace surrounding Naval Air Station Kingsville (NQI) indicates that the airspace is designated as Class D with a ceiling of 2,500 feet. Class D airspace typically is established to protect aircraft operations in the vicinity of an airport with an operating control tower, and the ceiling specifies the maximum vertical limit of that airspace.

In this case, the designation of 2,500 feet means that operations within this Class D airspace are controlled from the surface up to, but not including, that altitude. This means that pilots must receive clearance to enter or operate in this airspace, and it is crucial for ensuring safety where controlled traffic exists, especially in a military airspace context.

Understanding these designations is essential for pilots navigating near controlled airports, as it influences flight planning and procedures to comply with air traffic control requirements.