sentence1: At around 14:00 UTC today, a man climbed over the perimeter fence and made his way onto the North runway, 27R, at London's  Heathrow Airport, the United Kingdom's largest airport. The man, who was carrying a rucksack, then attempted to run in front of a plane on the runway,  however it is believed that he was tackled to the ground by armed police before reaching the wide runway.
sentence2: The number of security screeners in US airports will be reduced.