The biggest disadvantage of the volunteers in the Korean battlefield is that they do not have air supremacy, and when they entered the Korean war, our air force had just been formed, and they were in a state of lacking everything, and they were not yet able to participate in the battle. At that time, there was only one antiaircraft artillery regiment of the air defense unit that entered the DPRK, so the US bombers dared to unscrupulously drop bombs on our heads, especially the bombing of our rear communication lines and transport vehicles, making it difficult to transport logistical materials and seriously affecting the front-line volunteer soldiers. The formation of a powerful air force has become the unanimous desire of our army. Most of the first planes of our army came from the Japanese army. After Japan's unconditional surrender, our army entered the northeast in advance, searched everywhere for Japanese equipment and buried aviation materials, and then assembled them into airplanes through patchwork. By June 1946, more than 120 sorties of various aircraft had been found. But these planes are also in tatters, can only be used for training, and due to the lack of spare parts and fuel, they are often bombed by **, so they cannot play much role. 
It was not until October 25, 1949 that Liu Yalou became the commander of the Air Force, and on November 11, the Chinese Air Force was formally established, and 6 aviation schools were quickly established, and the Chinese Air Force began to take shape. However, the selection and training of pilots is a very long process, and the aircraft also requires a series of supporting measures such as ground support, machine repair, logistics, radar, and communications. By the time the Chinese Volunteers entered the Korean War, the Chinese Air Force barely had two fighter aviation divisions, one bomber regiment, and 117 combat aircraft of various types. The most important thing is that the average flight time of pilots is less than 100 hours, while the international practice of training pilots should be at least 300 hours, and the US military pilots with harsh conditions are even more than 500 hours. This group of pilots who graduated from the crash course had no actual combat experience and flew old fighters, so naturally they could not compete with the experienced US Air Force. In order to avoid the waste of air force strength, it was finally decided that the air force would not participate in the operation for the time being, but still step up training, and wait for the right time to fight with the Soviet army, learning and practicing at the same time. 
And just as the Volunteer Army was getting ready to go, the Soviet Union reneged on its promise to provide air cover. Despite this, our volunteers still played the slogan of "Resist US Aggression and Aid Korea, Defend the Homeland and Defend the Country" and resolutely left for Korea on October 19, 1950. Stalin, who learned the news, was extremely moved and praised him repeatedly: "The Chinese comrades deserve to be true Marxists and internationalists. Perhaps impressed by the courage of the volunteers, he initially only promised to provide ** equipment, but after the victory of the first battle of the volunteers in Korea, the fighters piloted by the Soviet army also began to appear in the sky near the Yalu River, and even crossed the Yalu River to provide cover for the rear communication line of our volunteers. In 1950, when China and the Soviet Union negotiated the purchase of fighter planes, the Soviet Union only agreed to provide China with MiG-9 fighters, which were eliminated after the Soviet army was replaced with MiG-15s. At the outbreak of the Korean War, most of the US Air Force was equipped with F-84 fighters, and in a skirmish with the US military near the Yalu River, our Air Force found that the overall performance of the MiG-9 was inferior to the US F-84, and it was at a disadvantage in air confrontation. The MiG-9 has a range of only 800 kilometers and a combat radius of only 320 kilometers, which is far inferior to the F-84;Although the MiG-9 airborne ** is powerful, it has a small bomb load and cannot fight for a long time. 
Under such circumstances, even if our air force completes its training and conducts operations against the DPRK, it will be difficult to take advantage. The adviser of the Soviet Air Force reported the situation to Stalin, who severely criticized the people involved in the negotiations and sent a telegram to Beijing on May 22, 1951, saying that in order to make the Chinese fighter aviation division more combat-effective, the MiG-15 should be used to replace the MiG-9 fighter. For this, the USSR needs to send you 372 MiG-15 aircraft. We have not been able to do this because of the lack of aircraft, but now we have been able to do so, and we intend to provide you with these 372 MiG-15 aircraft free of charge, and we will only pay the freight from the Soviet Union to China, and we will ...... itYou're guaranteed to get all 372 planes by the beginning of August. The MiG-15 was the most advanced fighter of the Soviet army at that time, for which Beijing expressed great gratitude. Stalin sent another telegram to Beijing on May 26 to explain the reasons for providing the Chinese MiG-15 free of charge, and frankly admitted that the previous sale of the MiG-9 to China was a mistake: we made a mistake: it was originally estimated that the MiG-9 could compete with the best British and American jet fighters. Now, after the air war in North Korea, the error of this estimate is evident ......Since the responsibility for this mistake lies entirely with us, it is incumbent upon us to eliminate our mistake and replace the MiG-9 with the MiG-15. 
At the same time, he also said that the replacement MiG-9s were originally intended to be shipped back to the Soviet Union, but the significance of these planes staying in China is obviously greater than that of returning to China. So he decided that the MiG-9s would also remain in China and could be used to train pilots or deal with U.S. bombers. During the War to Resist US Aggression and Aid Korea, the Soviet Union provided China with aircraft and other military advisers, and trained a large number of pilots for China. China has also obtained a part of the Soviet Union's manufacturing authorization and flight equipment manufacturing technology. In August 1951, in order to gain the initiative at the negotiating table, the "United **" launched the "Summer Offensive". Li Qiwei, commander-in-chief of the "United Peace Army," keenly discovered that the weak point of the Chinese People's Volunteers was that it was difficult to guarantee logistical materials, so he launched a "strangulation war" with the air force and carried out wanton and indiscriminate bombardment of our rear communications. At this time, the Air Force of our Volunteer Army was also ready to conduct large-scale air battles. The first large-scale air battle was carried out by the 4th Division of the Chinese Air Force, which had a total of 56 pilots and 55 MiG-15 fighters. 
On 25 September, the US Air Force dispatched more than 100 planes divided into five formations to bomb the communication line around China's Sinanju Bridge. The Soviets dispatched 110 planes to meet the attack, and asked the 4th Air Division to dispatch 16 planes to coordinate operations. In the fierce battle, Li Yongtai, the leader of the first brigade, was besieged by four enemy planes, and after being hit by 35 bullets, he was still able to land safely on the fighter plane. Pilot Liu Yongxin, after shooting down an American F-86 with 1 enemy and 6 enemies, finally died heroically due to being outnumbered. Hua Longyi, commander of the Second Brigade, destroyed two US planes within one minute of the engagement, and fought his way out of the 14 enemy planes that swarmed in, and after damaging two enemy planes, the planes were damaged and had to parachute. During the War to Resist US Aggression and Aid Korea, the 4th Air Force Division shot down 64 enemy planes and damaged 24 sorties. The 3rd, 2nd, and 14th Divisions of our Air Force also took turns to fight US planes in the skies over North Korea. The appearance of the Chinese and Soviet air forces over the DPRK greatly shocked the US Air Force, and the "MiG corridor" was established over the plain from Yalu to the Cheongchon River, which became a forbidden area for US aircraft. In the face of MiG-15 fighters, the US F-84 can only switch to bombing missions and adopt the more advanced F-86. Vandenberg, chief of staff of the US Air Force, said in amazement: "China has become one of the world's leading air powers almost overnight." ”
At the same time, with the large number of equipment of the Volunteer Army's air defense, the US bombers no longer dared to dive and bomb at low altitudes, but bombed at a high altitude of more than 3,000 meters, and their efficiency dropped significantly. After our railroad soldiers entered the court, they also showed amazing energy. Few roads and bridges blown up by the U.S. military have remained unrepaired for more than 24 hours. The supplies of the Volunteer Army were gradually restored, and the "strangulation war" of the US army could only end in failure. As time went on, the aerial bombardment of the US military became more difficult to be effective. In the preparatory stage for the Battle of Jincheng in June 1953, the logistics units of our army rushed to the front line in less than 10 days150,000 tons, including 1.3 million rounds of various artillery shells, laid a solid foundation for the victory of the battle. In the War to Resist US Aggression and Aid Korea, China's air force had 10 fighter aviation divisions, 21 regiments, and 2 bomber aviation divisions and 3 brigades participating in the war. 2,457 combat sorties were taken, 330 enemy aircraft were shot down and 95 were damaged. Our troops were shot down 231 aircraft, 151 were damaged, and 116 air crew members were killed. It not only covered the combat of the volunteers, but also gained valuable practical experience. 
To this day, there are still many voices questioning the correctness of the War to Resist US Aggression and Aid Korea, in fact, these people only see the ** they have paid, but they have not seen the gains that cannot be described by numbers. In a short period of two or three years, China's air force has grown from scratch and from weak to strong, not only training an air force capable of winning battles, but also safeguarding the security of China's coastal airspace and making great contributions to the country's stable development. Moreover, China's aviation industry can be said to be stepping on the shoulders of giants to develop, in order to achieve today's achievements in a short period of time. From this point of view alone, the decision made back then was undoubtedly very correct.