Improvements in or relating to onboard equipment for aircraft and the like

摘要

An emergency lighting system for an aircraft comprises networked light units 501 that communicate wirelessly with a master controller 502 to switch the light units 501 on in an emergency Each unit 501 has its own battery power source and is arranged to conserve power consumption by cycling between an operable (awake) condition in which it can communicate with the master controller 502 and an inoperable (sleep) condition wherein the wake-up time is approximately 1 millisecond or less.