AMC 25.809(a) Emergency exit outside viewing

• ED Decision 2015/019/R found in: CS-25

AMC 25.809(a) Emergency exit outside viewing ED Decision 2015/019/R The requirement to provide a view of the outside in all ambient lighting conditions suggests the use of externally mounted lighting (although other means may be acceptable). In the landing -gear-collapsed cases, the rolling and pitching effects on the fuselage may redirect a fixed lamp’s beam away from the area illuminated in the all-landing-gears-extended condition. Furthermore, in the case of inflatable escape slides, the toe-end ground contact point will probably move in the opposite direction to that of the lamp beam. In recognition of these effects, and in order to maintain reasonable demands on the complexity and power of external lighting equipment, the rule does not require the entire viewable area to be visible in all ambient lighting conditions. The only specific illumination requirement is for the likely areas of evacuee ground contact, with all landing gears extended, for passenger exits. However, it is recommended that as large a field of view as is practicable should be provided, taking into account aspects such as fuselage curvature and door/window/hatch location, in order to provide the best chance to identify external evacuation hazards before exits are opened. In the case of a flight crew emergency exit, a flight deck window as conventionally configured, used in conjunction with a suitably accessible and powerful portable illumination device (e.g. flashlight) will provide an acceptable means for viewing the outside conditions. Flight deck seats, consoles, etc., as conventionally configured, are not considered to be obstructions in the meaning of this term in CS 25.809(a)(2) in the case where flight deck windows are the viewing means and the exit is an overhead hatch. Furthermore, it is considered that the distance between flight deck windows, as conventionally configured, and an overhead hatch is such that the criterion for the viewing means to be adjacent to the exit is satisfied. [Amdt 25/17]