On June 10, 1940, Birchall was responsible for the capture of an Italian merchant ship, the "Capo Nola", in the Gulf of Saint Lawrence, hours after Canada declared war on Italy. Birchall had been tasked with locating any Italian vessels still in Canadian waters as the outbreak of war became imminent. On June 10, he found the "Capo Nola". Birchall had been informed of the declaration of war by radio so made a low pass over the freighter, as if making an attack. This panicked the captain into running his vessel aground against a sandbank. Birchall then touched down nearby and waited until Royal Canadian Navy vessels reached the scene. The "Capo Nola's" crew were the first Italian prisoners taken by the Allies during the war.