Also within each zone are portions of airspace, about 50 miles (80.5 km) in diameter, called TRACON (Terminal Radar Approach Control) airspace.

• 同样在每一个区域内都有多个直径约为50英里（80.；5公里）的小空域，叫做终端管制（终端雷达近场管制的简称）空域。