Smog disrupts flights to and from Beijing

A number of flights to Beijing were delayed or diverted to other airports over the weekend due to heavy smog enveloping the capital.

Flight HU7602 from Shanghai's Hongqiao International Airport circled over Beijing for 90 minutes on Saturday night waiting for wind to disperse the smog but had to divert to Jinan in eastern Shandong Province as it was running low on fuel, Hainan Airlines said. Some 60 flights to Beijing were diverted in a 2-hour period from 11pm on Saturday.

The Air Quality Index in Beijing surged to 470, or "severely polluted" on Saturday night and visibility was down to 200 meters at Beijing Capital International Airport. Conditions were even worse at nearby airports with visibility at Tianjin and Shijiazhuang just 50 meters.

Under civil aviation rules, both airport and pilot have to have a top level "blind landing" qualification before landing is allowed in visibility less than 200 meters. No airport in China has the qualification.

Pilots who fly to and from the country's top 10 airports, including Shanghai's Pudong and Hongqiao as well as Beijing have had to hold a level-2 qualification since January 1 this year. This allows landing in visibility between 200 and 400 meters.

However, a senior pilot with Spring Airlines said landing in low visibility would be risky even with the top qualification and most pilots prefer to circle to see if conditions improve.

The flights diverted from Beijing to Shanghai, Jinan, Shenyang and Taiyuan between 11pm and Saturday and 1:33am yesterday were mostly domestic but some international flights were also affected. China Eastern Airlines flight MU750 from Japan's Hokkaido to Beijing arrived over the capital around 11:30pm to find it could not land. It eventually landed at Qingdao in Shandong Province at 12:06am.

Russian Aeroflot flight SU200 circled over Beijing for 90 minutes around midnight waiting for an expected cold front to disperse the smog. It managed to land when conditions improved.

That cold front cleared the air in Beijing, Tianjin and across Hebei Province. Visibility had risen to 800 meters by 2am yesterday and diverted flights began to take off for the capital again.

The cold front and rain should scatter pollutants in most parts of the country over the next three days, but smog will return to north China and regions along the Yellow and Huaihe rivers when the cold front passes, according to forecasters at the National Meteorological Center.