Mainland airports and airlines are the worst for on-time departures and arrivals, according to a report that tracks air travel around the world.
More worrying is that their performance actually dropped in the past six months.
Beijing and Shanghai airports rank at the bottom of 35 major international airports surveyed in terms of flight delays and cancellations, according to the latest report by FlightStats, a popular US-based data provider on air travel.
The survey included a separate ranking of Asian airports.
Last month, only 18.3 per cent of the 22,019 flights departing from the Beijing Capital International Airport (PEK) were on time, FlightStats says in its latest report. It says 42 per cent of them saw delays of 45 minutes or more.
PEK was also the worst in January, with on-time departures at 29 per cent. Shanghai Hongqiao International Airport - the second worst on the list - had its on-time rate drop to 24 per cent from 38.9 per cent six months ago. Its ranking remained unchanged.
Hong Kong International Airport also reported a noticeable increase in flight delays and cancellations. Its ranking had dropped from 22 in January to 29 in June.
Serious delays were not limited to Beijing and Shanghai. None of China's provincial airports surveyed by FlightStats - including Guangzhou, Kunming , Nanjing , Chengdu, Changsha and Urumqi - could manage to get half of their flights on time.
By comparison, most airports in Japan have an on-time rate of 90 per cent or above. Haneda Airport in Tokyo, which tops the list, boasts 95 per cent, three points higher than six months ago.
Chinese airline performance was equally disappointing. China United Airlines had just 27 per cent of its flights arriving on time. It was closely followed by Xiamen and Shanghai airlines.
Large national carriers such as Air China and China Southern also reported massive delays. Mainland experts attribute the problem to excessive military control of the airspace and poor urban planning.
"Nearly 80 per cent of China's airspace has been reserved for military use. In other countries, such as the US, the situation is exactly the opposite," a senior executive of Hainan Airlines said.
"I am afraid that until a tragedy happens, the military will never be convinced to free up the airspace."
Zou Jianjun , of the Civil Aviation Management Institute of China, said the military was not the only reason for the delays.
He said major cities tried to monopolise the aviation business by diverting travellers from nearby cities to their airports.
This created a huge logjam for all major airports in China, while leaving the small-to-medium ones struggling.
Zou said the major airports put excessive stress on increasing passenger flow but did little to improve their management system to handle to rapidly increasing traffic.
"Quantity overrides quality. That is a common issue in China today," he said.
Although Beijing has tried to solve the delay problem for years, little has been achieved.
Serious delays often trigger violent protests. In recent months, there have been frequent reports of angry passengers smashing airline counters and attacking ground staff in an outbursts of anger.
Many have given up air travel altogether and opted for other transport, particularly high-speed rail.