A Japanese aircraft experienced a significant ground loop during takeoff from Ashiya Air Base due to a malfunctioning second engine. The pilot initiated a controlled ground loop maneuver, but failed to decelerate effectively on the wet runway, resulting in overrunning the runway and a crash landing at the edge of a slope. The aircraft’s maintenance condition prevented the ability to reverse the props.A Japanese aircraft experienced a significant ground loop during takeoff from Ashiya Air Base due to a malfunctioning second engine. The pilot initiated a controlled ground loop maneuver, but failed to decelerate effectively on the wet runway, resulting in overrunning the runway and a crash landing at the edge of a slope. The aircraft’s maintenance condition prevented the ability to reverse the props.