Development of Chinese Nationalist air force ( 1937 – 45 ) The Republic of China Air Force ( ROCAF ) was formed by the Kuomintang after the establishment of the Aviation Ministry in 1920 . As tensions mounted between China and Imperial Japan in the 1930s , a number of smaller Chinese warlord airforce men and equipment became integrated into the ROCAF in a centralized effort to counter Imperial Japanese military ambitions . During the Second Sino - Japanese War ( 1937 – 1945 ) , the ROCAF participated in attacks on Japanese warships on the eastern front and along the Yangtze river including interdiction and close - air support for the Battle of Shanghai in 1937 . Initially , the Chinese frontline fighter aircraft were mainly Curtiss Hawk IIs and IIIs and Boeing P - 26 Cs . These engaged Japanese fighters in many major air battles beginning on14 August 1937 , when Imperial Japanese Navy warplanes raided Chienchiao airbase ; " 814 " has thus become known as " Air Force Day " . Chinese Boeing P - 26 / 281 fighters engaged Japanese Mitsubishi A5M fighters in the world ' s first dogfight between all - metal monoplane fighters . A unique mission in April 1938 saw two Chinese Martin B - 10 bombers fly a mission over Japan , but dropping only anti - war leaflets over the Japanese cities of Nagasaki and Saga . It was a war of attrition for the Chinese pilots , as many of their most experienced ace fighter pilots , such as Lieutenant Liu Tsui - Kang and Colonel Kao Chih - Hang , were lost . Six months into the war , which is considered the beginning of World War II in Asia , the Chinese Air Force inventory of frontline American Hawk IIs and IIIss and P - 26Cs were superseded by faster and better armed Polikarpov I - 15 s and I - 16 s as support from the Soviet Union grew and American support faded . Through attrition and loss of their most experienced fighter pilots in the first half of the Second Sino - Japanese War , the Republic of China Air Force ultimately suffered irreversible losses in combat against the Japanese , and by the beginning of 1942 the ROCAF was practically annihilated by Japanese aircraft , particularly with the introduction of the Mitsubishi A6M Zero . The ROCAF was eventually supplemented with the establishment of the American Volunteer Group ( known as the " Flying Tigers " ) with heavily armed and armored Curtiss P - 40 Warhawks , and subsequently rebuilt each year following Imperial Japan ' s attack on Pearl Harbor with new aid and vigor from the United States . The Sino - Japanese War started on 7 July 1937 . At that time , Chinese sources estimated the Japanese could field approximately 600 aircraft ( from a total of 1 , 530 ) against China ’ s 230 combat aircraft . During the first phase up to 1939 , aerial bombing of enemy bomber formations was tried with indifferent results , and leaflet - dropping raids carried out over Japanese cities . The Japanese bombing raids were also fiercely contested , sometimes with significant Japanese losses . After suffering heavy losses in the Battle of Wuhan in October 1938 , most air force units were withdrawn for reorganisation and training . The ROC Air Force was reconstituted into seven Groups , one separate Squadron and four Volunteer Groups . In 1940 , the Russian Volunteer Group was stood down . By the end of 1941 , the air force had 364 operational aircraft . Up to 100 of these were P - 40B s operated by the American Volunteer Group . U . S . replacement aircraft began to arrive in March 1942 . They included A - 29 s , P - 40s , P - 43 s , and P - 66 s , and in 1945 B - 25 s , B - 17 s , and P - 51 Bs and - Ds . In 1944 , the USAAF U . S . 15th Air Force commenced joint operations in the China theatre . By this time the Chinese Air Force was mostly equipped with current operational aircraft types and was superior in all respects to the opposing Japanese air forces which remained . Foreign Aid . Soviet Union . From 1937 to the beginning of 1941 , the Soviet Union served as the primary supplier to the ROCAF , and from October 1937 to January 1941 , a total of 848 aircraft in 13 batches were ordered by the Chinese government and were supplied on credit , worth roughly 200 million dollars . In addition , there were 37 aircraft transferred to Chinese when Soviet force withdrew from China after the signing of Soviet – Japanese Neutrality Pact . These aircraft included 563 fighters , including 252 I - 152 , 75 I - 153 , 132 I - 16 Type 10 , 75 I - 16 Type 17 and rest being I - 15 bis , which was not part of the purchase in the 13 batches . Also included were 322 bombers , including 179 SB - 2M - 100A , 100 SB - 2M - 103 24 DB - 3 , 6 TB - 3 and 13 SB that were not part of the purchase in the 13 batches ) . Also included in the 13 - batch purchase were 5 UT - 1 trainers . However , of the 250 - 300 combat aircraft supplied annually , only a few dozen would survive through the end of the year . United States . While the USSR provided most of the military aircraft to Chiang Kai - shek in the late 1930s , many early Chinese aircraft were supplied by the American Curtiss Aeroplane and Motor Company . In 1937 the Hawk II and Hawk III biplanes comprised the backbone of Chinese fighter aviation . These were soon followed by the Hawk 75 monoplane . The demonstration model Hawk 75N , with non - retractable landing gear was purchased in 1938 and became the personal aircraft of the American advisor to the Aviation Committee , Claire Chennault who oversaw training and lobbied for the procurement of American aircraft . The entry of the USA into the war with Japan at the end of 1941 led to the receipt of Lend - Lease equipment from the United States , including aircraft . American Lend - Lease aviation equipment had already begun to arrive in China as early as the middle of 1941 , though that includes the first shipments before January 1942 which arrived under the guise of purchases . Including previously purchased American aircraft , US soon replaced USSR as the largest supplier for the Chinese Nationalist air force during the war ( Including the Second Sino - Japanese War that actually broke out in 1931 when Japan invaded Manchuria ) . The US aircraft supplied to China in its struggle against the Japanese invaders included : A - 12 , A - 17 , A - 19 , A - 29 , B - 10 , B - 17 , B - 24 , B - 25 , B - 29 , C - 19 , C - 43 , C - 45 , C - 46 , C - 47 , C - 100 ( Gamma 2E light bomber version ) , Curtiss F11C Goshawk , P - 12 , P - 26 , P - 36 , P - 38 , P - 40 , P - 43 , P - 47 , P - 51 , P - 61 , P - 66 , and PB4Y . Retraining on American aircraft occurred for the most part in India . ( Karachi and other cities ) , where Chinese pilots were sent both as groups and as entire units . As early as the end of 1941 Chinese pilots , mainly recently graduated from flight schools , began to be sent to the USA for longer training and mastery of American aircraft . The first American P - 43A fighters were received by the 4th Air Group ( 21st - 24th Squadrons ) in March 1942 . They retrained in Kunming , but for the new aircraft the pilots sequentially flew in small groups to India . On 24 April the deputy commander of the 24th Squadron , Wu Zhenhua , crashed on the flight to Kunming . On 12 May , Chen Lokun , the flight commander of the 24th Squadron was killed during a training flight , crashing into a tree during landing . In July for unclear reasons the P - 43 of the 4th Air Group commander , Zheng Shaoyu , caught fire in the air and the pilot was killed . On 3 August 1942 during a training flight the deputy group commander Chen Sheng crashed . A similar series of crashes accompanied the mastery by the Chinese of almost every new machine . ( It is notable that in Chinese sources the family names are given only of the perished commanders of various ranks , while the losses amongst the line pilots are hardly even noted . ) Concluding their conversion to the P - 43 A in early August 1942 , the group returned to Chengdu . In February 1943 , preparing for transition to the new American air equipment , the Chinese transferred to India the primary training groups from their flight schools . Only training for reconnaissance and photography continued to be carried out in China . In March 1945 the cadets completing primary training in India were sent to America to train further . By that time the number of cadets dispatched had reached 1224 , of whom 384 managed to return to China and participate in combat . In all , from 1942 to 1945 420 training aircraft were sent from the USA to China through India , including 20 AT - 6 , 8 AT - 7 , 15 AT - 17 , 150 PT - 17 , 127 PT - 19 , 70 PT - 22 , and 30 BT - 13 , and also 10 Beechcraft D - 17 medical aircraft . Domestic assembly . While the modified Hawk 75M with retractable landing gear was created specially for China , it was not widely used in the war against the Japanese , in spite of the fact that 30 aircraft , and 82 kits for assembly were delivered in the summer and autumn of 1938 . It was planned to assemble the Hawk in a factory operated by the Central Aircraft Manufacturing Company , which had been evacuated from Hankou to Loiwing . The latter location , not far from the Burmese border on the eastern bank of the Ruiluqiang River in Yunnan Province , at that time seemed protected from Japanese attacks , but technical difficulties plagued the actual assembly of the Hawk 75 in that location . Although the Japanese had not bombed the factory , only eight machines were assembled by October 1940 . The fate of the remaining kits is unknown . Following the failure of Hawk 75 production , the CAMCO factory planned to organize assembly of the export version of the Curtiss - Wright CW - 21 Demon , light fighter . Three aircraft and 32 sets of components were ordered from the USA . The factory at Loiwing worked until April 1942 , when on account of Japanese attacks it had to be evacuated to Kunming , while its American personnel set up shop in India . From 1943 to 1946 the aircraft factory , which was dispersed in the ravines neighboring Kunming , assembled an experimental series of nine fighter monoplanes , probably from components of the Hawk 75M and 75A - 5 , and CW - 21 . To a degree they were similar to the American prototypes and their further fate is unknown . In western sources the first example figures under the strange designation XP - 0 .