The day the skies went silent Air traffic controllers talk about 9/11 August 12, 2002 Posted: 11:30 PM EDT (0330 GMT) Green dots represent planes in the air in these air traffic control maps from 8:30 and 11:30 a.m. September 11. -------------------------------------------------------------------------------- (CNN) -- Shortly after American Airlines Flight 11 slammed into the World Trade Center's North Tower at approximately 8:46 a.m., air traffic controllers knew another plane was minutes away from the same deadly objective. They knew because, as with Flight 11, they had lost communications with United Flight 175 and were watching their radar screens as the second...