22.14En route Obstacles. Objects located beyond 15 km radius of the aerodrome are normally considered to be obstacles to aircraft in flight only if they exceed 150 m in height. Prominent objects of less height may be regarded as obstacles if they are on or adjacent to routes regularly used by helicopters. En route obstacles are usually lit by steady red lights at night and high intensity flashing white lights by day. Environmental considerations may preclude the use of high intensity lights.

22.15Marking of Overhead Wires or Cables. Overhead wires or cables are marked by coloured spheres.

Visual Aids for Denoting Restricted Use Areas

22.16 Closed Runways and Taxiways. A ‘closed’ marking shall be displayed on a runway or taxiway, or portion thereof, which is permanently closed to the use of all aircraft. A closed marking should be displayed on a temporarily closed runway or taxiway or portion thereof, except when the closing is of short duration and adequate warning by air traffic services is provided. On a runway a ‘closed’ marking shall be placed at each end of the runway, or portion thereof, declared closed, and additional markings shall be so placed that the maximum interval between markings does not exceed 300 m. On a taxiway a closed marking shall be placed at least at each end of the taxiway or portion thereof closed. The marking shall be white when displayed on a runway and shall be yellow when displayed on a taxiway. (Note: When an area is temporarily closed, frangible barriers or markings utilizing materials other than paint or other suitable means may be used to identify the closed area). When a runway or taxiway or portion thereof is permanently closed, all normal runway and taxiway markings shall be obliterated. Lightings on a closed runway or taxiway or portion thereof shall not be operated, except as required for maintenance purposes.

© Susumu Tokunaga

Figure 22.6 Closed runway

22.17 Non-load-bearing Surfaces. Shoulders for taxiways, holding bays and aprons and other non-load-bearing surfaces which cannot readily be distinguished from load-bearing surfaces and which, if used by aircraft, might result in damage to the aircraft shall have the boundary between such areas and the load-bearing surface marked by a taxi side stripe marking.

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22.21Response Time. The operational objective of the RFF service should be to achieve a response time of not exceeding 3 minutes to the end of each runway, as well as to any other part of the movement area, in optimum conditions of visibility and surface conditions. Response time is considered to be the time between the initial call to the RFF service, and the time when the first responding vehicle is in position to apply foam at a rate of at least 50% of the discharge rate specified. To meet the operational objective as nearly as possible in less than optimum conditions of visibility it may be necessary to provide guidance for RFF vehicles.

22.22Emergency Access Roads. Emergency access roads should be provided on an aerodrome where terrain conditions permit their construction, so as to facilitate achieving minimum response times. Particular attention should be given to the provision of ready access to approach areas up to 1000 m from the threshold, or at least within the aerodrome boundary. Where a fence is provided, the need for convenient access to outside areas should be taken into account. Note: Aerodrome service roads may serve as emergency access roads when they are suitably located and constructed.

22.23Fire Stations. All RFF vehicles should normally be housed in a fire station. Satellite fire stations should be provided whenever the response time cannot be achieved from a single fire station. The fire station should be located so that the access for RFF vehicles into the runway area is direct and clear, requiring a minimum number of turns. Providing the response time (22.20) can be met, the fire station need not be within the aerodrome confines.

Other Aerodrome Services

22.24 Apron Management Service. When warranted by the volume of traffic and operating conditions, an appropriate Apron Management Service (not to be confused with Ground Control), should be provided on an apron by an aerodrome ATS unit, by the aerodrome operating authority, or by a co-operative combination of these. Commercial operations providing the Apron Management Service also provide refuelling, de-icing, baggage and cargo handling and passenger transportation where busses are used. When the aerodrome control tower does not participate in the apron management service, procedures should be established to facilitate the orderly transition of aircraft between the apron management unit and the aerodrome control tower. Typically, when the flight is ready to depart, the pilot will call Ground Control and request engine start. This serves not only as a request to actually start the engines, but also to notify ATC that administratively and from an engineering point of view, the flight is ready to commence. At this point the tug would be coupled to the aeroplane and the ‘crew chief’ would be on external intercom. The pilot would then request “push back” and when approved the aircraft will move out on to the taxiway. At the same time the engines will be started and when the flight deck crew is satisfied that all is well, the tug will be disconnected and the nose-wheel steering reconnected. When this has been completed the crew chief will confirm that all panels are secure and that he is now unplugging his intercom lead. An apron management service shall be provided with radiotelephony communications facilities. Where low visibility procedures are in effect, persons and vehicles operating on an apron shall be restricted to the essential minimum. An aircraft stand shall be visually monitored to ensure that the recommended clearance distances are provided to an aircraft using the stand. The purpose of the apron management service is to:

•Regulate movement with the objective of preventing collisions between aircraft, and between aircraft and obstacles;

•Regulate entry of aircraft into, and co-ordinate exit of aircraft from, the apron with the aerodrome control tower, and

Obstacle Marking and Aerodrome Services 22