Ostfriesland and the limits of the result

Navy, Marine Corps, and Army aircraft attacked Ostfriesland over two days in July 1921. After the July 20 attacks, the ship settled by the stern and developed a list, while rough seas delayed the observers' inspection. On July 21, five bombers dropped 1,100-pound bombs and scored three direct hits before the later heavy-bomb attack. The aircraft were attacking an unmanned, non-maneuvering ship without anti-aircraft fire or onboard damage control. The sinking established that bomb damage could be lethal under the test conditions, but it could not prove battleship obsolescence under wartime conditions.