Until two weeks ago, Khalaf also worked as a baggage screener at George Bush Intercontinental Airport.
"I've been screening your bags for the past six months, and you don't even know it," said Khalaf, who also said Thursday that he is not really a terrorist and that his rhymes are exaggerations meant to gain publicity.
Andrea McCauley, a spokeswoman for the regional Transportation Security Administration office in Dallas, said the agency checks criminal records before hiring screeners, but it does not investigate what people do in their spare time.
"We have eyes and ears in the workplace," McCauley said. "Once we discovered these Web sites, we fired him."
An Internet search of Khalaf's name brings up Web sites that feature his obscene, violent and misogynistic raps that threaten to fly a plane into a building on Sept. 11, 2005.