Day by day chronology
MONDAY, 5 JUNE 1939
(Red Army) Soviet Red Army General Zhukov arrives and takes command at Tamsagbulag.
SATURDAY, 24 JUNE 1939
(JAAF) Ki-15 reconnaissance flight by Lt. Col. Mayoshi of the 10th Sentai over Tamsagbulag and Tamsagbulag Airfield. Observed are 135 aircraft including 4 TB-3 heavy bombers.
TUESDAY, 27 JUNE 1939
(JAAF) In the morning a large Japanese force of bombers led by Lt. General Giga including 9 x Ki-30 of the 10th & 16th Sentai,
9 x Ki-21of the 61st Sentai plus 12 x BR.20 of the 12th Sentai escorted by 74 x Ki-27 from the 24th Sentai flying top cover atack Tamsagbulag and Tamsagbulag Airfield. On the ground at Tamsag, Soviet forces were surprised by the arrival of the enemy aircraft and I-15 and I-16s were scrambled to intercept, and a massive dogfight involving over 150 planes unfolds. Soviets lost three I-15s.