Chinese pilots looking to arrive in Beijing will need landing qualifications when new rulings come into effect on January 1st.

From the new year, flights entering the capital from any of the ten busiest airports in the country, on days when visibility is around 400 metres or less, must be flown by a pilot qualified to use an instrument landing system.

This is because Beijing often has smog and by having more pilots capable of landing, the Civil Aviation Administration of China hopes to reduce flight delays.

A source told the China Daily newspaper: "It is part of a series of measures the administration took recently to raise the flights' on-time performance."

The new requirements will only be imposed on domestic flights, although it is not known how many services currently have the landing system installed.

Visibility was reduced in London earlier this week, with many flights grounded at Heathrow due to strong fog in the morning, while other services were redirected.