最早的重要课题或与敌人交战、或在敌占区飞行的军用飞机——战斗机、侦察机、攻击机、轰炸机等等,尽量避免被敌人发现是理所当然的。尽早发现敌人而推迟被敌人发现是飞机作为军用以来的重要课题。第一次世界大战时,敌人主要依靠肉眼发现目标。特别是飞机在太阳光的照射下闪闪发光,很容易被发现。但是如果背对太阳,或者巧妙地利用云彩就可以不被发现,从而保持有利的态势。当时这种方法得到了人们的广泛利用。 The earliest important issue or military aircraft fighter or reconnaissance aircraft, attack aircraft, bomber aircraft, etc. that fought enemies or flew in enemy occupied areas should be taken as a matter of course to avoid being discovered by the enemy as far as possible. The early detection of the enemy and the delay in the discovery by the enemy are important issues for the military since the aircraft was used. During the First World War, the enemy mainly relied on the naked eye to find its target. In particular, the aircraft glittering in the sunlight, it is easy to find. However, if the back to the sun, or skillfully use the cloud can not be found, thus maintaining a favorable situation. At that time this method has been widely used by people.