10. Issuance of air traffic control clearances
10.1 Departing aircraft
10.1.1 Area control centres shall forward a clearance to approach control offices or aerodrome control towers with the least possible delay after receipt of request made by these units, or prior to such request if practicable.
10.2 En-route aircraft
10.2.1 Air traffic control clearances must be issued early enough to ensure that they are transmitted to the aircraft in sufficient time for it to comply with them.
10.2.2 Aircraft on flight plans specifying that the initial portion of the flight will be uncontrolled, and that the subsequent portion of the flight will be subject to air traffic control by an area control centre after the control area of origin, shall be advised to contact the area control centre in whose area controlled flight will be commenced for clearance.
10.2.3 Aircraft on flight plans specifying that the first portion of the flight will be subject to air traffic control, and that the subsequent portion will be uncontrolled, shall normally be cleared to the point at which the controlled flight terminates.
10.2.4 An area control centre may request an adjacent area control centre to clear aircraft to a specified point during a specified period.
10.2.5 After the initial clearance has been issued to an aircraft at the point of departure, it will be the responsibility of the appropriate area control centre to issue an amended clearance whenever necessary and to issue traffic information if required.
10.2.6 During the transonic and supersonic phases of a flight, amendments to the clearance should be kept to a minimum and must take due account of the operational limitations of the aircraft in these flight phases.
10.2.7 When so requested by the pilot, an aircraft shall be cleared for cruise climb whenever traffic conditions and co-ordination procedures permit. Such clearance shall be for cruise climb either above a specified level or between specified levels.
10.2.8 When so requested by the pilot, an aircraft should, in so far as practicable, be authorized to absorb a specified period of notified terminal delay by cruising at a reduced speed for the latter portion of its flight. The specified period may be the whole or part of the notified terminal delay.
10.2.9 Where an aircraft files, at the departure aero-drome, flight plans for the various stages of flight through intermediate stops, the initial clearance limit will be the first destination aerodrome and new clearances must be issued for subsequent portions of the flight.
10.2.9.1 The flight plan for the second stage, and that for each subsequent stage, of a flight through intermediate stops will become active for ATS and SAR purposes only when the appropriate ATS unit has received notification that the aircraft has departed from the relevant departure aerodrome, except as provided for in 10.2.9.2.
10.2.9.2 By prior arrangement between air traffic control units and the operators, aircraft operating on an established schedule may be cleared through intermediate stops provided, if the proposed route of flight is through more than one control area, scheduled aircraft may be cleared through intermediate stops within other control areas only after co-ordination between the area control centres concerned.
11. Contents of air traffic control clearances
11.1 Clearances shall contain positive and concise data and shall, as far as practicable, be phrased in a standard manner. 中國航空網 www.k6050.com 航空翻譯 www.aviation.cn 本文鏈接地址：Rules of the Air and Air Traffic Services(43)
