This 1971 technical reference page from a U.S. Air Force weapons delivery manual provides ballistic data for high-drag ('hi-drag') deliveries of the Mk-82 and Mk-117 retarded bombs, weapons designed with retarding fins or parachutes to allow low-altitude release while avoiding the aircraft's own fragmentation pattern. Used by F-4 Phantom aircrew flying from Da Nang Air Base during the Vietnam War, this data was essential for accurate low-level bombing runs against ground targets. Project: 218451