Service aérien de l'Armée impériale japonaise
With the rise of the radical "Kōdōha" faction under Sadao Araki to the post of Army Minister, Sugiyama was sidelined to the Imperial Japanese Army Air Service in March 1933. However, the failed coup d'etat of the February 26 incident in 1936 led to a purge of the "Kōdōha" from positions of authority and Sugiyama was promoted to full general in November 1936.