Heathrow passenger numbers hit record level BAA, owners of the airport, said Heathrow is at 99.2pc capacity after there were 476,197 flights in 2011 against an annual limit of 480,000. "Capacity constraints are damaging the UK economy today when the country can least afford it," said Colin Matthews, BAA chief executive. As the UK's only international hub airport, Heathrow is central to developing our trade links with fast-growing emerging markets. A new hub airport has been proposed in the South East, but this has a projected cost of £50bn and may take decades to build. During this time we would be handing over on a plate the UK's historic trade advantages to our European competitors. Passenger numbers grew 5.5pc compared to 2010 and ahead of the previous annual record of 67.9m passengers in 2007. However, in December growth accelerated to 15pc because of the snow in 2010. December 2011 was Heathrow's busiest ever December despite the economic uncertainty. Edinburgh airport, which BAA is selling after a ruling by the Competition Commission, also had a record year. It served 9.4m passenger, beating the 9m record of 2009. Overall, BAA's traffic rose 4.4pc to 108.5m. However, when disruption in 2010 from strikes, snow and the Icelandic volcanic ash cloud is taken into account the underlying growth was reduced to 0.9pc.