Eles usam o poder do aeroporto. O aeroporto e seus equipamentos importantes têm energia de reserva e / ou uma usina dedicada (que por sua vez terá planos de reserva).
Isso é o que a FAA diz:
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
Basicamente, é para evitar o desligamento de um grande aeroporto . Selecione os aeroportos e as pistas devem poder operar.
A ICAO recomenda a mesma coisa e lista os critérios que os aeroportos precisam cumprir no Anexo 14, seção 8.1 Fonte de alimentação secundária.
Por exemplo:
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.
Para as ajudas não incluídas em um aeroporto, o Anexo 10 da OACI, Volume I, Parte I, Capítulo 2, trata das recomendações.