What is the purpose of a light gun signal in aviation?

The purpose of a light gun signal in aviation is to communicate instructions when radio contact is lost. This visual signaling method is particularly vital in situations where pilots and air traffic controllers cannot use radio communication due to equipment failure or other circumstances. Light guns emit various signals—steady and flashing lights of different colors—conveying specific instructions, such as whether to taxi, take off, or hold. This system ensures that even without verbal communication, essential directives can be conveyed effectively and safely to pilots.

The other options do not capture the primary function of light gun signals; for instance, they are not designed for passenger communication or indicating weather conditions. Additionally, while light signals may be involved in the takeoff process, they are not specifically used to signal takeoff but rather to provide comprehensive instructions when standard communication fails.