Norden bombsight
Based on costly lessons in the Pacific theater, concerns were raised about the ability of the armor on these battleships to withstand aerial bombing, particularly high altitude bombing using armor piercing bombs. Developments such as the Norden bombsight further fueled these concerns. While the design of the "Iowa"s was too far along to adequately address this issue, experience in the Pacific theater eventually demonstrated that high altitude unguided bombing was ineffective against maneuvering warships.