De använder flygplatseffekten. Flygplatsen och dess viktiga utrustning har reservkraft och / eller en dedikerad kraftverk (som själv har säkerhetskopieringsplaner).
Detta är vad FAA säger:
The FAA recognizes the need to have a reliable power source to operate NAVAIDs, even during utility power outages. Order 6030.20 establishes Continuous Power Airports (CPAs) that provide continuous operations in the event of an area-wide utility failure. Backup power to designated runways at these airports must be able to supply power for at least 4 hours for runway lighting as well as navigation, landing and communication equipment. In addition, FAA policy also requires that power systems used for support of Category (CAT) II and CAT-III operations must be capable of transferring to an alternate source within one second.
Source: AC 150/5300-13A
Det är i grund och botten att undvika att stänga av en viktig flygplats . Välj flygplatser och landningsbanor måste kunna fungera.
ICAO rekommenderar samma sak och listar de kriterier som flygplatser behöver möta i bilaga 14, avsnitt 8.1, sekundär kraftförsörjning.
Till exempel:
8.1.5 Recommendation.— Requirements for a secondary power supply should be met by either of the following:
— independent public power, which is a source of power supplying the aerodrome service from a substation other than the normal substation through a transmission line following a route different from the normal power supply route and such that the possibility of a simultaneous failure of the normal and independent public power supplies is extremely remote; or
— standby power unit(s), which are engine generators, batteries, etc., from which electric power can be obtained.
För navaids i allmänhet som inte ligger inom en flygplats hanterar ICAO Annex 10, Volume I, Del I, Chapter 2 rekommendationerna.
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