Carlos Viegas Gago Coutinho, GCTE, GCC (1869–1959), known as Gago Coutinho, was a Portuguese geographer, cartographer, naval officer, historian and aviator. An aviation pioneer, Coutinho and his pilot, Artur de 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, using a Fairey IIID seaplane named “Santa Cruz.”
Coutinho invented a type of sextant incorporating two spirit levels to provide an artificial horizon. This adaptation of the traditional marine sextant allowed navigation without visual reference to the real horizon.
