SHANGHAI • Nearly half the flights leaving the main international airport of China's commercial hub Shanghai were delayed in August, regulators said, punishing the facility by denying it new routes.

Air travel in the country is booming as incomes rise, but the sector scores poorly in customer satisfaction, and flight delays are constant. This is often blamed on the military, which controls most of the skies over the country.

Only 51.16 per cent of departures from the Shanghai Pudong airport left on time in August, according to figures from the Civil Aviation Administration of China (CAAC).

"If I leave from Pudong airport on time, it is like winning the jackpot. A two-hour delay is normal," a woman going by the name Jenny WoW posted on her microblog.

Said another netizen: "Every time I fly from Pudong, it is miserable, sitting for two or three hours doing nothing even on a clear day. I was always told it was air traffic control."

The airports of Hangzhou in Zhejiang province, and Tianjin, the northern port next to Beijing, ranked second- and third- worst for delays, the CAAC said. As a sanction, both airports and Pudong were this month denied increases in the number of flights, and charters and applications for new routes, it said.

According to the FlightStats website, the average delay in August at Pudong - the world's 19th-busiest airport last year by passenger traffic - was 75.6 minutes.

Chinese social media is filled with tales of poor traveller behaviour, at times sparked by delays. In January, police detained 25 angry passengers who opened aircraft emergency exit doors before take-off after their departure was delayed by snowfall.

AGENCE FRANCE-PRESSE