The Doolittle Raid was conceived by US Army Air Force Colonel James Doolittle as a morale-boosting attack against the Japanese home islands in early 1942. His idea was to have 16 Army B-25 Mitchells fly off at maximum range from a US Navy carrier and bomb various Japanese cities. They would then fly on and land in friendly areas in China. After training, the bombers were embarked on USS 'Hornet', which set off for Japan, covered by her sister carrier USS 'Enterprise' and some cruisers and destroyers. The raid achieved minimal results in terms of physical damage but its psychological impact was critical.