Fragmented engines make early carrier aviation expensive

Hosho's early air group mixed the Napier Lion-powered B1M, a Hispano-derived engine in the 1MF fighter, and a related Hispano variant in the 2MR reconnaissance aircraft. The 2MR belonged to an early phase when carrier aircraft were being considered for gunnery spotting. The fighter and reconnaissance machine came closest to engine commonality, but even they used different variants. This small air group therefore created a costly maintenance and spare-parts burden. Akagi and Kaga offered more storage, yet their larger size did not end the practice of supporting a diverse collection of engines.