People on the no-fly list, managed by the FBI's Terrorist Screening Center, are prohibited from boarding a commercial flight for travel into or out of the United States.

The number of people on the list is classified, CNN said. An official with knowledge of the government's figures told CNN in 2012 that the list contained about 21,000 names, including about 500 Americans.

Before the change, American citizens and permanent residents who inquired with the government about being denied aircraft boarding received a letter that neither confirmed nor denied their inclusion on the no-fly list. Now, they'll be made aware of their status if they apply for redress, with an option to request further information, CNN reported. 

"The U.S. government is making enhancements to the Department of Homeland Security Traveler Redress Inquiry Program (DHS TRIP) to provide additional transparency and process for U.S. citizens and lawful permanent residents who have been denied boarding on a commercial aircraft because they are on the No Fly List," the Department of Homeland Security said in a statement. In cases in which travelers included on the list request to receive or submit more information about their status, the government will provide a second, more detailed response, identifying "specific criterion under which the individual has been placed on the No Fly List," according to the court documents.  An unclassified summary of that information will be provided "to the extent feasible, consistent with the national security and law enforcement interests at stake," court papers said.

Those who appear on the no-fly list will then have further opportunity to dispute their status in writing, with supporting materials or exhibits, and will receive a final written decision from the Transportation Security Administration, said the CNN report. 

http://www.cnn.com/2015/04/15/travel/americans-no-fly-list-feat/