June 26, 1960
On 26 June a detachment of ten Yak-7B's and two IL-l0's moved from P'yŏngyang to Sinmak. The Ilyushin and Yakovlev aircraft were obsolete in a jet air age, but they were good conventional aircraft. Many of the North Korean pilots were young volunteers with limited flying experience, but they were cocky, aggressive, and eager to fight. The NKAF was "young" and incompletely trained, but it was clearly an offensive force. On the eve of hostilities FEAF stated that the North Korean Air Force had the capability to destroy the meager ROKAF and then materially to assist the North Korean ground troops as they moved into South Korea.
Despite the secrecy that surrounded Communist activities, the Korean Military Advisory Group (KMAG) received some hints that Chinese-trained units had been joining the North Korean army.