Long before radios and modern avionics made in-flight communication routine, aircrews relied on standardized hand and light signals to communicate emergencies. This page, dated July 1971, details the visual signal procedures used by jet squadrons -- likely F-4 Phantom crews operating from bases such as Da Nang -- to convey critical information like aircraft emergencies, electrical failures, and bailout intentions when radios failed, a vital safety backstop during the intensive air operations of the Vietnam War. Project: 218454