A man looks out the window at airplanes

A man looks out the window at airplanes at Ronald Reagan Washington National Airport in Arlington, Virginia, just outside Washington, DC, on December 29, 2009. Security measures have been heightened at airports after a Nigerian man attempted a terrorist attack on a Northwest Airlines flight on Christmas Day in Detroit. Yemen confirmed on Tuesday that Umar Farouk Abdulmutallab, who has been charged with trying to blow up a US-bound airliner, was still in the country just weeks ago, after the local Al-Qaeda branch claimed the attempted bombing. AFP PHOTO / Saul LOEB (Photo credit should read SAUL LOEB/AFP/Getty Images) horizontal,usa,adult,looking,window,men,washington dc,airplane,airport,virginia,terrorism,ronald reagan washington national airport,arlington – virginia,outs