He scored all of his victories flying in the Nieuport 11, becoming one of the most successful pilots in the type. Stoppani made a career of aviation. He became an instructor with SAI, first at Foggia, then at Passignano sul Trasimeno in 1925. In 1927, he moved to Trieste and resumed test piloting, for SISA Airline. He then became the chief test pilot for CANT aircraft company until mid-World War II, circa 1943. During his career with CANT, he was closely associated with designer Filippo Zappata; the association led to Stoppani making fifteen first flights and setting 41 flying records. Stoppani was awarded both a Silver and Gold Medal for Aeronautical Valor for his efforts. He still holds the distance record for a seaplane in a closed circuit; in 1937, he covered 3,231 miles without landing, piloting a CRDA CANT Z.506. After World War II, he worked for Breda and SIAI Marchetti. Mario Stoppani died on 20 September 1959.