| 释义 |
airspace Class F airspace Class FAirspace in which both IFR (instrument flight rules) and VFR (visual flight rules) flights are permitted. All participating IFR flights receive an air traffic advisory service, and all flights receive flight information service if requested. This is uncontrolled airspace, which lies on advisory routes 10 NM wide between navigational aids on reasonably busy upper-level routes. This classification of airspace does not exist in the United States. |