Map: Aerial crossing Lisbon-Rio de Janeiro by the Portuguese Marine officers Gago Coutinho - Sacadura Cabral

Offered by the Ministry of Navy. In 1919, Gago Coutinho, engineer Geographer, encouraged by Sacadura Cabral, who had already planned the air journey to Brazil, began dedicating to the progress of air navigation methods. Perform accurate measurements of position in flight unavailable sea horizon available became difficult with a vulgar sextant. To solve the problem, Gago Coutinho conceived the first sextant with artificial horizon (materialized through a level of air bubble) that could be used aboard aircraft, and called 'precision astrolabia'. Improved this instrument, came to be manufactured and widespread by the German builder C. Plath with the name of 'System Admiral Gago Coutinho'. In collaboration with Cabral Sacadura conceived and constructed another instrument to which they called 'abortion plaque' or 'broker of direction', which allowed graphically calculating the angle between the longitudinal axis of the aircraft and the course below, considering the intensity and direction of the wind. To prove the effectiveness of its methods and instruments, Gago Coutinho and Cabral Sacadura made several air travel, including a Lisbon trip - Funchal in 1921, in about seven and a half hours. The journey that has finally demonstrated the whole world the value of these instruments and methods was the aerial crossing of the South Atlantic, between Lisbon and Rio de Janeiro, in the Lusitanian seaplane, between March 30 and June 17, 1922.