World War II Allied names for Japanese aircraft The World War II Allied names for Japanese aircraft were reporting names , often described as codenames , given by Allied personnel to Imperial Japanese aircraft during the Pacific campaign of World War II . The names were used by Allied personnel to identify aircraft operated by the Japanese for reporting and descriptive purposes . Generally , Western men ' s names were given to fighter aircraft , women ' s names to bombers , transports , and reconnaissance aircraft , bird names to gliders , and tree names to trainer aircraft . The use of the names , from their origin in mid - 1942 , became widespread among Allied forces from early 1943 until the end of the war in 1945 . Many subsequent Western histories of the war have continued to use the names . History . During the first year of the Pacific War beginning on 7 December 1941 , Allied personnel often struggled to quickly , succinctly , and accurately identify Japanese aircraft encountered in combat . They found the Japanese designation system bewildering and awkward , as it allocated two names to each aircraft . One was the manufacturer ' s alphanumeric project code , and the other was the official military designation , which consisted of a description of the aircraft plus the year it entered service . For example , the military designation of the Mitsubishi A5M fighter was the " Navy Type 96 Carrier Fighter " . Type 96 meant that the aircraft had entered service in Imperial year 2596 , equivalent to Gregorian calendar year 1936 . Other aircraft , however , which had entered service the same year carried the same type number ; aircraft such as the Type 96 Carrier Bomber and the Type 96 Land Attack Bomber . Adding to the confusion , the US Army and US Navy each had their own different systems for identifying Japanese aircraft . In mid - 1942 , Captain Frank T . McCoy , a United States Army Air Forces military intelligence officer from the 38th Bombardment Group assigned to the Allied Technical Air Intelligence Unit in Australia , set out to devise a simpler method for identifying Japanese aircraft . Together with Technical Sergeant Francis M . Williams and Corporal Joseph Grattan , McCoy divided the Japanese aircraft into two categories ; fighters and everything else . He gave boys ' names to the fighters , and the names of girls to the others . Later , training aircraft were named after trees , single engine reconnaissance aircraft were given men ' s names and multi - engine aircraft of the same type were given women ' s names . Transports were given girls ' names that all began with the letter " T " . Gliders were given the names of birds . McCoy ' s system quickly caught on and spread to other US and Allied units throughout the Pacific theater . By the end of 1942 , all American forces in the Pacific and east Asia had begun using McCoy ' s system , and British Commonwealth nations adopted the system shortly thereafter . The list eventually included 122 names and was used until the end of World War II . To this day , many Western historical accounts of the Pacific War still use McCoy ' s system to identify Japanese aircraft . In an effort to make the names sound somewhat comical , McCoy gave many of the aircraft ' hillbilly ' names , such as " Zeke " and " Rufe , " that he had encountered while growing up in Tennessee . Others were given names of people the creators of the system knew personally ; the Mitsubishi G4M bomber , with its large gun blisters was named " Betty " in homage to a busty female friend of Williams . The Aichi D3A " Val " got its name from an Australian Army sergeant . Not all of McCoy ' s chosen names caught on . Many Allied personnel continued calling the Mitsubishi Navy Type 0 Carrier Fighter " Zero " instead of McCoy ' s name of " Zeke . " Also , McCoy ' s name for an upgraded version of the Zero , " Hap , " in tribute to US Army general Henry H . Arnold , had to be changed to " Hamp " when it was learned that Arnold disapproved .