What is the primary function of formation lights on military aircraft?

Formation lights on military aircraft are primarily designed to aid in close flying formation. These lights help pilots maintain visual awareness of their relative positions to each other during night operations or low-light conditions. The lights are typically located on the wings and tail of the aircraft, providing clear and visible guidance to pilots flying in tight coordination with one another.

This function is critical in ensuring that the aircraft can fly safely and effectively in formation, which is essential for various military operations, including tactical maneuvers and formation flying during missions. By ensuring that each aircraft can see the others easily, formation lights contribute to enhanced safety and operational efficiency.

The other options relate to functions that are not the primary focus of formation lights. While they may provide some level of visibility in other contexts, the main purpose is specifically to assist in flying formations closely.