spaschal on DSK3GDR082PROD with CFR

Section 25.812

14 CFR Ch. I (1-1-19 Edition)

when the assist means is erected, the
emergency lighting system must be designed as follows.
(1) The lights must be operable
manually from the flight crew station
and from a point in the passenger compartment that is readily accessible to a
normal flight attendant seat.
(2) There must be a flight crew warning light which illuminates when power
is on in the airplane and the emergency
lighting control device is not armed.
(3) The cockpit control device must
have an  - on, -   - off, -  and  - armed -  position so that when armed in the cockpit
or turned on at either the cockpit or
flight attendant station the lights will
either light or remain lighted upon
interruption (except an interruption
caused by a transverse vertical separation of the fuselage during crash landing) of the airplane-s normal electric
power. There must be a means to safeguard against inadvertent operation of
the control device from the  - armed -  or
 - on -  positions.
(g) Exterior emergency lighting must
be provided as follows:
(1) At each overwing emergency exit
the illumination must be - 
(i) Not less than 0.03 foot-candle
(measured normal to the direction of
the incident light) on a 2-square-foot
area where an evacuee is likely to
make his first step outside the cabin;
(ii) Not less than 0.05 foot-candle
(measured normal to the direction of
the incident light) for a minimum
width of 42 inches for a Type A
overwing emergency exit and two feet
for all other overwing emergency exits
along the 30 percent of the slip-resistant portion of the escape route required in Section 25.810(c) that is farthest
from the exit; and
(iii) Not less than 0.03 foot-candle on
the ground surface with the landing
gear extended (measured normal to the
direction of the incident light) where
an evacuee using the established escape
route would normally make first contact with the ground.
(2) At each non-overwing emergency
exit not required by Section 25.810(a) to have
descent assist means the illumination
must be not less than 0.03 foot-candle
(measured normal to the direction of
the incident light) on the ground surface with the landing gear extended

where an evacuee is likely to make
first contact with the ground outside
the cabin.
(h)
The
means
required
in
SectionSection 25.810(a)(1) and (d) to assist the occupants in descending to the ground must
be illuminated so that the erected assist means is visible from the airplane.
(1) If the assist means is illuminated
by exterior emergency lighting, it
must provide illumination of not less
than 0.03 foot-candle (measured normal
to the direction of the incident light)
at the ground end of the erected assist
means where an evacuee using the established escape route would normally
make first contact with the ground,
with the airplane in each of the attitudes corresponding to the collapse of
one or more legs of the landing gear.
(2) If the emergency lighting subsystem illuminating the assist means
serves no other assist means, is independent of the airplane-s main emergency lighting system, and is automatically activated when the assist
means is erected, the lighting provisions - 
(i) May not be adversely affected by
stowage; and
(ii) Must provide illumination of not
less than 0.03 foot-candle (measured
normal to the direction of incident
light) at the ground and of the erected
assist means where an evacuee would
normally make first contact with the
ground, with the airplane in each of
the attitudes corresponding to the collapse of one or more legs of the landing
gear.
(i) The energy supply to each emergency lighting unit must provide the
required level of illumination for at
least 10 minutes at the critical ambient
conditions after emergency landing.
(j) If storage batteries are used as the
energy supply for the emergency lighting system, they may be recharged
from the airplane-s main electric power
system: Provided, That, the charging
circuit is designed to preclude inadvertent battery discharge into charging circuit faults.
(k) Components of the emergency
lighting system, including batteries,
wiring relays, lamps, and switches
must be capable of normal operation
after having been subjected to the inertia forces listed in Section 25.561(b).

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VerDate Sep<11>2014

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