Airports Commission says Britain should build third Heathrow runway

By Sarah Young LONDON (Reuters) - Britain should build a third runway at London's Heathrow Airport, a government-appointed commission into the country's airport capacity said in a report that could cause a political headache for Prime Minister David Cameron. After a three-year study, the Airports Commission selected a new runway at Heathrow over two other shortlisted options, arguing that it offered Britain the best way to add "urgently required" long-haul routes to new marke