Jet Stream in Apocalyptic Wasteland

Thirty years ago, an event swept the entire world, causing the world's population to plummet to less than 2 billion. The population density on the continent dropped to less than 8 people per square kilometer. As a result, many large cities dried up, and the surviving towns and villages became post-apocalyptic strongholds, but the connections between the strongholds were blocked by mountains, deserts, Gobi and wide waters. In order to continue human civilization, people established air channels between strongholds and relied on collecting and replicating old-era aircraft to maintain various exchanges between strongholds. At the same time, local armed forces that used old-era fighter planes appeared and grew rapidly. In order to suppress these local armed forces, they also rebuilt their own air forces... High-temperature jets appeared again in the doomsday wasteland.