The Transatlantic Flights performed at 1919 proved to be a tremendous success; however, aerial navigation over ocean was based on radio equipment. Sextants were very difficult to use, and methods of calculations were quite time-consuming to provide positioning results of an aircraft at great speeds. For these reasons the Aerial Astronavigation was considered unsuitable. 3 years later, two Portuguese airmen managed to perform the First Aerial Crossing of the South Atlantic exclusively achieved by Aerial Astronavigation in an unprecedent route precision achievement; such feat was a milestone in Aviation History, marking the debut of the sextant as a key mean for air navigation: for the first time, sextant, course corrector and methods of calculations proved their effectiveness and value for aerial navigation. Reports of the 1st South