Sitting here in central Taiwan, I bet on my VHF scanner I can hear
flights above China talking to controllers, if they are high enough in
the air. Frequencies to monitor would be Hong Kong 121.3,
Guangzhou=?, Shanghai=?, Xiamen=?, Fuzhou=?. A Google search failed.

I also notice 118-136 Mhz. reception conditions vary from day to night
and even hour to hour.

Any chance of military monitoring too?