The Korean People's Army Air Force, (Chosŏn'gŭl: 조선인민군 공군; Hanja: 朝鮮人民軍 空軍), is the appellation of the unified aviation forces of North Korea. The KPAF is the 2nd largest branch of the Korean People's Army comprising an estimated 110,000 personnel members. It possesses 940 aircraft of different types; mostly of Soviet and Chinese origin. Its primary task is to defend North Korean airspace. When the People's Army was forged with Soviet assistance, the aviation unit became its air force branch on August 20, 1947. North Korea has celebrated August 20 as Air Force Foundation Day ever since.