Home Current News Japan built monster plane-carrying subs to attack US cities during World War...NewsCurrent NewsJapan built monster plane-carrying subs to attack US cities during World War II, but they never fired a shotNovember 8, 202091FacebookTwitterPinterestWhatsApp The enormous I-400-class submarines were supposed to carry planes and launch air raids on US cities, but the tide of the war turned on Japan.Source: yahoo.com/news