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(a) Adequate primary power supply must be available at aerodromes for the safe functioning of air navigation facilities.
(b) For aerodromes that are referred to in rule 139.5(aa)(1), the design and provision of electrical power systems for the aerodrome visual and radio navigation aids must be such that an equipment failure will not leave pilots with inadequate visual and non-visual guidance or misleading information.
(a) For a precision approach runway, a secondary power supply capable of meeting the requirements specified in Table H-1 for the appropriate category of precision approach runway must be provided. Electric power supply connections to those facilities for which secondary power is required must be so arranged that the facilities are automatically connected to the secondary power supply on failure of the primary source of power.
(b) For a runway meant for take-off in runway visual range conditions of less than 800 m, a secondary power supply capable of meeting the relevant requirements of Table H-1 must be provided.
(a) For a runway meant for use in runway visual range conditions of less than 550 m, the electrical systems for the power supply, lighting and control of the lighting systems included in Table H-1 must be so designed that an equipment failure will not leave the pilot with inadequate visual guidance or misleading information.
(b) Where the secondary power supply of an aerodrome is provided by the use of duplicate feeders, such supplies must be physically and electrically separate so as to ensure the required level of availability and independence.
(c) Where a runway forming part of a standard taxi-route is provided with runway lighting and taxiway lighting, the lighting systems must be interlocked to preclude the possibility of simultaneous operation of both forms of lighting.
Where lighting systems are used for aircraft control purposes, such systems must be monitored automatically so as to provide an indication of any fault which may affect the control functions. This information must be automatically relayed to the air traffic service unit.
| Runway | Lighting aids requiring power | Maximum switch-over time | Notes |
|---|---|---|---|
| Precision approach category I | Approach lighting system | 15 seconds | |
| Runway edge | 15 seconds | c | |
| Visual approach slope indicators | 15 seconds | a,c | |
| Runway threshold | 15 seconds | c | |
| Runway end | 15 seconds | ||
| Essential taxiway | 15 seconds | a | |
| Obstacle | 15 seconds | a |
