On September 13, China Civil Aviation Network issued a notice stating that Beijing and its surrounding areas will activate a permanent no‑fly zone on September 20. The no‑fly zone has a radius of 300 km, covering airspace from the ground up to unlimited altitude and operates around the clock. Except for civil aviation flights and emergency rescue, all other flight activities are restricted. The notice points out that this measure does not affect the public’s ability to travel by air. The notice includes a navigation notice photo marked “Civil Aviation North China Air Traffic Management Bureau”, with the validity period column marked “PERM”.