[8] These volunteers included future ace-fighter pilots Art Chin, John "Buffalo" Huang, Wong Pan-Yang, plus Hazel Ying-Lee (who was not allowed to fly in combat as a female), Louie Yim-qun, Chan Kee-Wong et al.[9][10] As the battles of Shanghai, Nanjing, Taiyuan, and other regions dragged on near the end of 1937, the initial Chinese Air Force inventory of mostly American-made aircraft had become largely depleted, and the Soviet Union came to China's aid by supplying the bulk of aircraft to the Chinese Air Force for the next four years of war under the Sino-Soviet Treaty of 1937, and dispatching a Soviet Volunteer Group of aviators to assist with the combat operations in China; Chinese fighter pilots having mostly converted into the Polikarpov I-15 and I-16 series of fighter aircraft by early-1938.

[15] At the outbreak of full-scale conflict of the Second Sino-Japanese War/World War II in August 1937,[16] the Chinese Air Force had 645 combat aircraft, of which about 300 were fighter planes.

While seeking to better compete against the highly advanced Mitsubishi A5M fighters of the IJNAF, Colonel Kao Chih-hang on a morale-boosting shakedown of his men and performance-boosting of his machines, had his maintenance crews remove the bomb-racks, fuel tank cowlings, landing lights, etc., to save weight and reduce drag off the Hawks, and on 12 October 1937, he led an aggressive seek-and-destroy mission consisting of six Hawk IIIs, two Boeing P-26/281 "Peashooters", and a Fiat CR.32 in the opportunity to engage any approaching Japanese fighter aircraft.

On 20 February 1939, thirty Japanese bombers flying in 3 formations were intercepted over Lanzhou by 40 USSR volunteer and Chinese fighters taking off in small groups at 5-minute intervals.

The massive IJAAF and IJNAF joint-strike terror-bombing campaigns and all-airwar which began in earnest on 3 May 1939 under the codename Operation 100 (100 号作战) as the Chinese Air Force was reorganizing from the Battle of Wuhan.

In December 1939, the USSR fighter group, up to 50 planes under the command of S. P. Suprun was transferred to south Yunnan where Japanese air attacks on communications lines along the Chinese portion of the Burma Road had become more intense.

On 26 May, Japanese fighters encountered 18 I-15s from the 29th Pursuit Squadron flying from Gansucheng to Lanzhou; two I-16s were shot down, both pilots bailing out, and the other 16 I-16s were destroyed on the ground when they landed for refuelling.

Since World War II erupted in Europe on 1 September 1939 after Nazi Germany invaded Poland, the United States had maintained its neutrality until the unannounced Japanese air attack on the American naval base at Pearl Harbor on 7 December 1941.

In December, Washington approved China's request to recruit American pilots who would resign from U.S. military services and volunteer to serve in the Chinese Air Force with significant monetary compensation.

The American Volunteer Group, better known as the Flying Tigers, was officially formed on 1 July 1941, consisting of three squadrons of 30 planes each under the direct control and command of Claire Lee Chennault.

For the next six months, the aerial battles of the Flying Tigers' P-40s with Japanese fighter and bomber aircraft were regular sights in the skies over south Yunnan and Burma.

On 3 September, a P-43 flown by Lieutenant Martin Cluck of the 75th Squadron had to abort a reconnaissance mission due to mechanical trouble, Japanese fighters attacked him at low altitude near the air base and riddled his P-43.

[36] On 30 December, three P-43s and six P-40s from the CATF flew an escort mission to Lashio, Burma; the P-43s provided top cover to the P-40s, enabling the P-40s to claim one of the six Japanese fighters encountered.

In the eight-month operations of the CATF from July 1942 to March 1943, they shot down 145 Japanese planes and 85 probables, and flew 65 bombing missions; they lost 16 P-40s and one B-25 Mitchell bomber.

Having just landed, Captain Chow Chin-kai, commander of the 23rd Squadron and veteran of many years combat ran from his P-40 to a P-66 parked nearby, and took off to attack the Japanese formation.

[36] Members of this unit including P-40N pilot Chen Bingjing escorted bombing missions against Japanese army positions in Vietnam beginning in October 1943.

Seeing no opposing interceptors and only minimum anti-aircraft gun fire, Lieutenant Colonel Irving Branch of the CACW led his flight of bombers on a sweep down low strafing the airfield.

They sank a motor launch, damaged two cargo vessels and a barge; one of the Japanese intercepting fighters from the 25th Sentai flown by Moritsugu Kanai shot down one P-38.

On 28 April, 26 B-24s from the 14th Air Force escorted by ten P-51 fighters carried out a bombing mission on the storage area north of Zhengzhou at the lower reaches of the Yellow River.

On 2 June in a battle at China's Central Plain, seven P-40Ns from the 7th fighter Squadron of the CACW made an attack on an airfield at Zhengzhou where a Japanese air transport unit was based.

Seven Japanese K-44 fighters of the 9th Sentai led by Captain Kobayashi intercepted the Chinese P-40Ns, and shot down five, including the one flown by the Flight Commander Zhang Lemin.

Capt Weng Xinhan, deputy commander of the 41st PS (the former French Volunteer Group Squadron that was disbanded in October 1938), died in course of the Battle of Gui-Liu on 12 September 1944 after being hit by anti-aircraft fire in his P-40, and crash-landing.

In the air battle, the Japanese destroyed one Chinese and three American P-40s while the CACW shot down six enemy planes; one of the pilots from the 49th Sentai reportedly parachuted from his burning Ki-84 but drowned in the Yangtze River.

Major Horace S. Carswell Jr. of the 308th Bomber Group was awarded the Medal of Honour for his action on that day when he attacked a Japanese convoy in the South China Sea under intense anti-aircraft fire.

During the concluding period of the war from January to June 1945, the Chinese pilots and their American counterparts participated actively in battles supporting ground forces on all fronts in central, southern and eastern China.

The CACW unofficial combat record in the time from its activation on 1 October 1943 to the end of the war in August 1945 included 190 Japanese aircraft destroyed in the air, 301 on the ground.

On 9 March about 50 fighters and bombers from the 14th Air Force on armed reconnaissance attacked railroad targets, river and road traffic, bridges, gun positions, and troops at several locations, particularly around Guiyi, Hengyang, Nanjing and Xinyang.

On 10 March about 60 fighters and bombers from the 14th Air Force hit targets in rivers, on roads and railroads, gun positions, warehouses, airstrips, and troops around Xinyang, Yiyang, Changsha, Qiyang, Yueyang, Hengyang in Hunan, and Hankou, and Wuchang in the neighboring Hubei province.

On 10 August, about 50 P-47s and P-51s from the 14th Air Force attacked river and railroad targets, troops, trucks, and bridges at several points in southern and eastern China.

On 18 August, the vice-commander of the 24th Pursuit Squadron from the Chinese Air Force, Guo Fengwu flew over Guisui (known as Hohhot after 1954) in Inner Mongolia to drop leaflets which contained the text of Japanese Emperor Hirohito's surrender decree.