释义 |
preferred IFR routes preferred IFR routesRoutes established between busier airports to increase system efficiency and capacity. IFR (instrument flight rules) clearances are issued on the basis of such routes except when severe weather avoidance procedures or other factors dictate otherwise. Preferred IFR routes are correlated with SID (standard instrument departures) and STAR (standard terminal arrivals) and may be defined by airways, high-level airways, direct routes between NAVAIDs (navigational aids) or waypoints, radials, DME (distance-measuring equipment) fixes, or any combination of these. |