CAT.IDE.A.275 Emergency lighting and marking
(a) Aeroplanes with an MOPSC of more than nine shall be equipped with an emergency lighting system having an independent power supply to facilitate the evacuation of the aeroplane.
(b) In the case of aeroplanes with an MOPSC of more than 19, the emergency lighting system, referred to in (a) shall include:
(1) sources of general cabin illumination;
(2) internal lighting in floor level emergency exit areas;
(3) illuminated emergency exit marking and locating signs;
(4) in the case of aeroplanes for which the application for the type certificate or equivalent was filed before 1 May 1972, when operated by night, exterior emergency lighting at all overwing exits and at exits where descent assist means are required;
(5) in the case of aeroplanes for which the application for the type certificate or equivalent was filed after 30 April 1972, when operated by night, exterior emergency lighting at all passenger emergency exits; and
(6) in the case of aeroplanes for which the type certificate was first issued on or after 31 December 1957, floor proximity emergency escape path marking system(s) in the passenger compartments.
(c) For aeroplanes with an MOPSC of 19 or less and type certified on the basis of the CAA’s certification specification, the emergency lighting system referred to in point (a) shall include the equipment referred to in points (1), (2) and (3) of point (b).
(d) For aeroplanes with an MOPSC of 19 or less that are not certified on the basis of the CAA’s certification specification, the emergency lighting system referred to in point (a) shall include the equipment referred to in point (b)(1).
(e) Aeroplanes with an MOPSC of nine or less, operated at night, shall be equipped with a source of general cabin illumination to facilitate the evacuation of the aeroplane.