What is the purpose of a light gun signal used by ATCT personnel?

The purpose of a light gun signal used by Air Traffic Control Tower (ATCT) personnel is primarily for communicating with aircraft and ground vehicles when radio contact has been lost or is not available. This visual communication method is particularly important in situations where verbal instructions cannot be conveyed, ensuring that operations can continue smoothly and safely even in the absence of radio communication.

Light gun signals consist of colored lights that convey specific instructions to pilots and vehicle drivers, such as whether to stop, proceed, or return, thus helping maintain safety and order in the airspace and on the ground. This system is a vital part of air traffic management and assists in preventing potential accidents that could arise from a lack of communication.