in three consecutive phases each targeting on a different area. The first phase from 22 July to 22 August concentrated on American air bases centered on Guilin, resulting in 50 American planes destroyed by the Japanese. The second phase began on 23 August, in which they targeted their attacks on Chongqing, Chengdu and eastern China air bases. At dawn on 23 August, 21 bombers escorted by 17 fighters took off from Hankou and were joined en route by another 14 fighters to strike an arsenal just to the west of Chongqing. A total of 29 fighters including ten P-40s, eight P-43s and 11 P-66s of the Chinese Air Force from the 4th and 11th Group at Peishiyi Airfield scrambled and took to the air to intercept. A flight of American fighters also scrambled from a distant air base but was too far to intercept. In the ensuing battle, the Japanese shot down two P-66s, one each of the P-40s and P-43s, and lost one bomber. The Chinese reported to have shot down three Japanese fighters and five bomber probables. In the third phase beginning in September, the Japanese resumed their attacks on targets in Guilin and Yunnan. As a part of the 14th Air Force, Chennault created a special unit known as the Chinese-American Composite Wing (Provisional) (CACW) under his command. The CACW comprised the 1st Bomber Group, and the 3rd and 5th Fighter Groups with American pilots, and Chinese pilots from the Chinese Air Force, as well as American and Chinese ground crews. Since many of the Chinese pilots were young pilots of the Chinese Air Force, who had recently returned after completion of their training in the United States, lacking any combat experience, the unit was under an American commander, assisted by a staff of Chinese officers. The CACW was officially formed on 31 July 1943, and activated on 1 October 1943. The newly formed CACW were sent to Karachi, India, where they were re-equipped with B-25s and new P-40Ns, and trained under American supervision. Members of this unit including P-40N pilot Chen Bingjing escorted bombing missions against Japanese army positions in Vietnam beginning in October 1943. On 25 November 1943, six B-25s from the 2nd Bomber Squadron of the CACW took off from Guilin at 6 am and staged through Suichwan, where they were refueled and joined by eight B-25s of the 11th Bomber Squadron and 16