 When the war broke out, Manado I Airfield, located just east of Manado City at Mapanget was still under construction.As part of the Japan's plan to conquer the Netherlands East Indies, particularly the island of Java, air support from southern Sumatra, Kuching, Banjarmasin (south-eastern part of Dutch Borneo), Makassar and Kendari (both on southern Celebes) was required.Beforehand, however, in order to set up the aforementioned aerial support, specifically in southern Celebes and Banjarmasin, relay fields in Manado, Tarakan and Balikpapan had to be conquered as well.