During World War II, the US Air Force, the USAAF (United States Army Air Force), was not an independent type of armed force and was formally under the command of the army. In the course of this conflict, they became the most powerful military aviation in the world, and at the time of the end of hostilities, they numbered about 2.25 million people! Due to the fact that the American aviation industry was one of the most modern and efficient in the world, the USAAF saw many successful, and sometimes great, aircraft models. It is worth remembering that in 1940-1945 it produced a total of approx. 295 thousand. machines, and therefore more than the aviation industry of Germany, Italy and Japan combined. Moreover, among these thousands of machines produced, one can point to the very successful P-38 Lightning, P-47 Thunderbolt or P-51 Mustang fighters, B-25 Mitchell or B-26 Marauder tactical bombers, but also the legendary B-17 Flying Fortress strategic bombers. and the B-29 Super Fortress. The USAAF pilot training system can also be considered successful and well-thought-out, as it was able to provide the rapidly expanding air force with well-trained pilots. It is also worth remembering that, unlike the German aviation, the American crews and pilots were rotated and after serving a certain period of time, they most often returned to the country, to training units, passing their experiences on. This fact may explain why American fighter aces (such as Richard Bong or Thoma McGuire) had "only" dozens of kills compared to several hundred kills of German aces (such as Erich Hartmann or Gerhard Barkhorn).