He then went on to live in Turyinsky before moving to Nadezhdinsk, where he worked as a steelworker and graduated from factory apprenticeship school in 1929.

[1] Soon after arriving in Spain in June 1937 as a flight commander in a fighter aviation group, Serov became among the first Soviet pilots to engage in aerial combat at night after a sortie with Mikhail Yakushin.

He returned in the USSR in January 1938, by then having totaled 150 sorties and been credited with eight solo aerial victories, including one at night.

[1] Not long after being awarded the title Hero of the Soviet Union on 2 March 1938 for his actions in Spain, he became head of the main flight inspectorate, and in April 1939 he graduated from advanced training for commanders at the Military Academy of General Staff.

[1] Serov was killed during a training flight with Polina Osipenko in a UTI-4 on 11 May 1939; during aerobatics the plane went into a tailspin and crashed despite almost recovering from the loss of control.