 In the 1930s and early 1940s , the Navy divided carrier @-@ borne bombers into two types : the torpedo bomber and the dive bomber , each with crews of two or three men . Wartime experience showed that pilots could aim bombs and torpedoes without assistance from other crewmembers as well navigate with the aid of radio beacons and the development of more @-@ powerful engines meant that faster aircraft no longer needed a rear gunner for self @-@ defense . Furthermore , the consolidation of the two types of bombers greatly increased the flexibility of a carrier 's air group and allowed the number of fighters in an air group to be increased . 
