Following the Japanese attack on Pearl Harbor on 7 December 1941, the 50th was re-designated the 431st Bombardment Squadron. In June 1942, shortly after the Battle of Midway, the 11th Group was authorized as a mobile force by the Army Air Forces in order to respond to a Navy request by Admiral Nimitz for long-range armed search planes support for locating Japanese fleets and with firepower to withstand defending Japanese fighter attacks while tracking the fleet. As a mobile group, the 11th Group received authorization to leave Hickam Field to support Navy operations in the South Pacific Theater during the Guadalcanal and Northern Solomon Islands Campaigns.