An aviation pioneer, Gago Coutinho and Sacadura Cabral were the first to cross the South Atlantic Ocean by air, in a journey from March to June 1922, started in Lisbon, Portugal, and finished in Rio de Janeiro, Brazil,[1] using a seaplane variant of the British reconnaissance biplane Fairey III.

Gago Coutinho was nominated head of the Geodesical Mission of Eastern Africa in May 1907, a post he held until the beginning of 1911.

The year after his return to Portugal, he was nominated the head of the Geodesical Mission of São Tomé and Príncipe, in 1915, which he was until middle 1919.

Artur de Sacadura Cabral had already delineated by them the project of making the first aerial crossing of the South Atlantic, meant to take place in 1922, the year of the centennial of the independence of Brazil.

The Fairey IIIB seaplane named Lusitânia used by Gago Coutinho and Sacadura Cabral for their transatlantic flight did not have enough fuel capacity to make the entire trip unaided so various stops were made along the way and the aviators were shadowed by a support ship, República.

On the journey down the Brazilian coast a heavy rain storm caused the aircraft's engine to fail and the aviators were forced to ditch in the ocean.

Tamlyn, en route from Cardiff to Rio, rescued Coutinho and Cabral; they completed their journey with a new aircraft.

Gago Coutinho invented a type of sextant incorporating two spirit levels to provide an artificial horizon.