第一航空戦隊
When "Hōshō" was completed, little thought was given to naval aircraft in an offensive role and moreover with only one carrier there was insufficient consideration given to carrier doctrine within the Japanese naval establishment. However, in 1928 the First Carrier Division was formed with three carriers and the study of the role of aircraft carriers in a naval engagement was initiated. Because of the short range of carrier aircraft at the time, many in the naval hierarchy were still very much surface oriented. They viewed carrier aircraft to be employed as support for the main battle fleet and not as offensive weapons. Aircraft were to act as scouts and spotters, layers of smoke screens for naval gunfire, fleet air defense, and later (with the increase in aircraft performance) as a means to attack battleships and other surface targets.