All very tightly controlled - its a communist state after all.
Don't let your liberal, free speach, what about my rights attitude get in the way of reality.
Can't have you flying about uncontrolled - you might drop pro-democracy/pro-Tibet independance leaflets.
You laugh........thats what happened when a certain flying school, in Hua Hin - Thailand private hired out its Partnavia.
Straight to Saigon....leaflet dropping. Upshot - can not hire any aircraft, privately from said school. without "extra pax" ie: said school employee/pilot on board.
Cheers