The CANT Z.511 was a four-engine long-range seaplane.
Originally designed for the Central and South Atlantic passenger routes, it was later adapted as a military transport and special raider.
The Z.511 had its first test flights at Monfalcone, Venezia Giulia between October 1940 and March 1942.
Between 28 February and 1 March 1942, test pilot Mario Stoppani succeeded in taking off and landing fully loaded in very rough seas, with 1.5 m (4.9 ft) waves and winds of 55–65 kilometres per hour (30–35 kn; 34–40 mph).
The Z.511 prototype was then transported to Grado, Venezia for further evaluations, the last test and operational flight occurred on 1 September 1943, two days before the Italian Armistice was signed.
After the division of the Italian forces, one aircraft was appropriated by the Fascist Aeronautica Nazionale Repubblicana.
However, it had been damaged only three weeks before by British fighters, which had strafed it on Lake Trasimeno where it was undergoing final trials.
It was transferred to the seaplane base at Vigna di Valle.
There it suffered from sabotage by base personnel to prevent it falling into the hands of either the Allies or the Germans.
The other aircraft, still under construction at the CRDA factory, was retained by Axis forces and scrapped for the metal, which was sent to Germany.
