Dubai International Airport is set to become the world’s second busiest international air hub in the next few months, placing it behind London Heathrow, currently the world’s busiest airport.

The Dubai airport is currently only the fourth busiest airport in the world, but forecasts by the Centre for Asia Pacific Aviation (CAPA) suggest that it will be second only to Heathrow on passenger traffic by November 2011. The Middle Eastern airport is currently undergoing extensive expansion works which are expected to make it the world’s largest airport, alongside upgrade works on existing terminals. The work is scheduled for completion by 2017.

Dubai International Airport is home to the Emirates airline, and has been boosted by its strong performance in recent years, and the carrier’s substantial investments into new aircraft, including Boeing’s A380 super-jumbo. The airport’s passenger numbers look set to take it close to Heathrow’s 1.5 million international seats offered in November 2011. The Dubai airport will offer 1.3 million international seats in the same period.

CAPA attributed the increase in popularity of the Dubai hub to both an increase in seasonal flights offered by Gulf airlines and the popularity of flights between Europe and Asia with connections in Dubai.

While Heathrow remains top for international seats offered, the world’s busiest airport overall, taking both international and domestic travel into account, is Atlanta’s Hartsfield-Jackson airport. Heathrow was overtaken in overall capacity by Beijing Airport earlier in 2011, according to analysts OAG.

Airport capacity is normally judged on a combination of actual passenger numbers, number of seats offered on aircraft flying into and out of the airport, as well as aircraft movements to and from the location.