Plus Ultra is a Dornier Do J flying boat which completed the first transatlantic flight between Spain and South America in January 1926 with a crew of Spanish aviators, that included: the major Ramón Franco, the captain Julio Ruiz de Alda Miqueleiz, the sub-lieutenant Juan Manuel Durán, and the mechanic Pablo Rada.

The Dornier Do J Wal ("whale") is a twin-engine German flying boat of the 1920s designed by Dornier Flugzeugwerke. The Do J was designated the Do 16 by the Reich Air Ministry (RLM) under its aircraft designation system of 1933.