The UAE has suspended all Iranian-airline flights. Oman and Iraq stopped accepting them. Turkey halted Mahan Air. Turkmenistan denied overflight to a Tehran–Dushanbe flight, forcing it back. Since the Sept 23
@SecScottBessent deadline, the region is closing to Iran's carriers.
China however has not. Mahan Air landed in Guangzhou on Sept 23 and still schedules Beijing, Shanghai and Shenzhen.
But here is the thing, a plane cannot land without fuel, handling and a counter. At Mahan's Chinese airports those services run through a few identifiable companies.
Several are large firms; a handful of Iranian flights a week is not worth their far larger non-Iran business and their banks should be asking questions. Here are the ones that are exposed to these sanctions:
中国航空油料有限责任公司 (China Aviation Oil Supply): fuel at Beijing Capital and Tianjin
深圳承远航空油料有限公司 (Shenzhen Chengyuan): sole fuel supplier at Shenzhen
上海浦东国际机场航空油料有限责任公司 (Pudong Aviation Fuel): fuel at Shanghai Pudong
华南蓝天航空油料有限公司 (South China Bluesky): fueling at Guangzhou Baiyun
广州白云国际机场地勤服务有限公司 (Baiyun Ground Handling) and 上海国际机场地面服务有限公司 (Shanghai International Airport Services): ramp and passenger handling
@USTreasury already designated Mahan's Shanghai agents (上海翼上, 上海马汉国际旅行社) in July. Any of the above still fueling or handling Mahan today is exposed to the same secondary sanctions that just emptied Dubai of Iranian aircraft.