Examination of Interior Aircraft Emergency Lighting Under Simulated Postcrash Fire and Smoke Conditions

This report presents the results of an examination of the effectiveness of emergency interior lighting in a wide-body test aircraft fuselage subjected to elevated temperatures and smoke conditions generated by an external fuel fire. Partial interior lighting systems and smoke photometers were installed in the Cl33 test aircraft fuselage and measurements were taken during the full-scale fire tests. Photometric measurements show significant stratification of smoke with the highest smoke density values at the ceiling. Test data indicate that the ceiling-mounted lights are obscured shortly after the start of a fire test. The external fuel fire may provide illumination levels greater than the required 0.05 foot-candle for emergency cabin illumination. Increasing the brightness of a sign or light may not significantly increase its visibility under smoke filled cabin conditions. Lowering signs or lights closer to the floor will increase their usefulness during times when the cabin area is filled with smoke. Lights on the floor that outline the aisle provide additional aid in locating exit passageways during times when the cabin is filled with smoke.