(1) Regional air traffic service routes or international routes are open routes determined according to the Asia-Pacific Navigation Plan of ICAO or determined by China. Its route direction is determined by the regional navigation meeting, and the route code is designated by the Asia-Pacific Office of ICAO, namely A, B, G and R..
(2) The regional navigation routes are also determined by the ICAO Asia-Pacific Navigation Plan, and the route codes are designated by the ICAO Asia-Pacific Office, which are L, M and N respectively. ..
(3) Domestic air traffic service routes are determined by the state and assigned codes, namely H and J. (4) Domestic regional navigation routes are determined by the state and assigned codes, namely Q (heading 180~359), Y (heading 360~ 179) and T (two-way).
(4) A Latin letter can be added before the basic code for the specified altitude range or for the flight of a specific aircraft. For example, K is used for helicopter low-altitude routes, U is used for high-altitude routes, and S is used for supersonic aircraft acceleration, deceleration and supersonic flight routes. You can also add a Latin letter after the basic code. For example, D means that the airline, airline or part of the flight segment only provides consulting services, and F means that the airline, airline or part of the flight segment only provides flight information services.