The Guardian - Airport admits it is struggling to cope with surge in demand and its new staff are not yet up to full speed. Heathrow has asked airlines to stop selling summer tickets and imposed a daily limit of 100,000 passengers departing the airport, as it struggles to cope with the surge in travel.The London hub has experienced chaotic scenes in recent weeks, as have many other UK airports, with long queue times amid shortages of ground staff and airlines cancelling thousands of flights.