Is there a nice way to tell a pilot his or her certificate has been pulled? The FAA and the Department of Homeland Security are quietly continuing a practice to bar pilots -- on the basis of "security concerns" -- from flying our friendly skies. The Associated Press reports that in July the Homeland Security Department directed U.S. and foreign anti-terrorism entities to review crew lists for foreign commercial flights using U.S. airspace. Sixteen pilots raised suspicions and five have been denied permission to fly into the United States. The agency, however, did not provide the reasons for the denials nor the names of the affected pilots. "It does not necessarily mean that they were in fact associated with terrorists, although it could be," Asa Hutchinson, undersecretary for border transportation, told the Associated Press. Hutchinson added the pilots could have simply overstayed previous visas or been connected to some crime in the past. The agency also said the pilots would have to reapply for visas to re-enter, but the likelihood of those being approved would be slim. To date, 13 foreign pilots have had their U.S. licenses taken away because of security considerations since the Sept. 11 terror attacks but seven of those appealed and three were reinstated after a review.