The regiment was first formed in May 1938 as the 12th Fighter Aviation Regiment, part of the 69th Fighter Aviation Brigade, in the Kiev Military District at Kirovohrad airfield from the 16th Separate Fighter Squadron. It was initially equipped with the Polikarpov I-16 and Polikarpov I-15bis. It fought in the Soviet invasion of Poland, where it shot down one Polish aircraft. In April 1940, Captain Pavel Terentyevich Korobkov, a Hero of the Soviet Union and Spanish Civil War flying ace, became the regiment's commander. In June, the regiment provided air cover for the Soviet occupation of Bessarabia. On 14 July, the regiment was transferred to the 15th Mixed Aviation Division. It became part of the 64th Fighter Aviation Division on 5 January 1941. On 22 June, Lieutenant Leonid Grigoryevich Butelin shot down one Junkers Ju 88 and rammed another over Ivano-Frankivsk Airfield while flying an I-153, the regiment's first kills of the war. Butelin was killed in the taran, for which he was posthumously awarded the Order of the Red Banner. The regiment fought in the Battle of Kiev and was sent to the rear for resupply. It was transferred to the 11th Reserve Fighter Aviation Regiment and was reequipped with the more modern LaGG-3 fighters at Rostov-on-Don in October. German advances forced the regiment to withdraw to Kirovabad in Azerbaijan SSR to continue training in November. After finishing reequipping, the regiment was sent to the Crimean Front as part of the 72nd Fighter Aviation Division and fought in the Defense of Sevastopol. On 26 December, the regiment was renamed as the 486th Fighter Aviation Regiment. Throughout its roughly six months of combat, the 12th IAP had made 2607 sorties, shot down 75 aircraft and destroyed a total of 97 aircraft. It had lost 61 aircraft and had ten pilots killed.