e., pilot's must know "what's going on" so that they can "figure out what to do (Adam, 1994,pp 148-156)." Moreover, the new technologies must be cost effective in terms of safety, survivability, and combat kills.
Perhaps the most significant events in the history of aircraft interior lighting have occurred within about the last decade. In the 1930s, aircraft instrument illumination was provided by indirect white floodlighting. These lights, however, produced undesirable reflections and glare. Then, in the late 1930s, ultraviolet light (UV) technologies were developed. UV illumination of fluorescent instrument markings, however, also had its own inherent flaws. Finally, 1941 saw the introduction of red cockpit lighting. Red light illuminated the instruments, but enabled the pilot to maintain outside night adaptation. For approximately two decades, all military aircraft employed this lighting strategy. It wasn't until the 1960s that the Air Force developed a "blue-filtered white incandescent light." This blue-white light ultimately led to a controversy among the military's different branches. Until only recently, both the Navy and Army rebuked the Air Force's blue in favor of red. Only with the introduction of night vision goggles (NVG) has the dispute been resolved. NVG systems require lighting that is devoid of red energy. This need has led to the uniform use of either monochromatic blue or blue-green lighting (Schmickley, 1992, pp. 3-4).
In both military and civil aviation, cockpit lighting can be subdivided into two components: primary and secondary lighting. Primary lighting involves the internal illumination of such things as instrument dials, indicators, and control panels. In contrast, secondary lighting refers to the cockpit's background ambient lighting.
Secondary lighting may consist of floodlights or spotlights providing area illumination. This light generally diminishes inversely with th...