This document provides a comprehensive historical account of the International Advisory Group - Air Navigation Services (ANSA) and shows the achievements, organizational changes, and contributions to the aviation industry. Established in 1967 by German air traffic controllers from the Rhein Control upper airspace ATC center, ANSA is a non-profit organization dedicated to improving air traffic control systems and procedures. Initially formed to support German air navigation authorities and EUROCONTROL, the group expanded its membership to include experts from over 20 countries. In 1985, ANSA moved its legal seat to Switzerland, continuing its mission to enhance flight safety and modernize ATC systems.