I just want to know a fact

I do not want to discuss if Chinese airforces should attack the enemy. The problem is according to your article, Chinese airforces kept in Chinese side but his article said our fighter jets were in vietnamese sky. Please read carefully the following paragraph:
战斗的主动权已牢牢掌握在我军手里，敌人只有挨打的份，没有还手之力。每天，有多少架次的战斗机在我们的头上飞过，开始，我们还躲一躲，后来，基本上不用躲了。教导员还说：以后看到飞机，不用隐蔽了，全是我们的空军，天空是晴朗的。