About a dozen U.S. citizens and lawful permanent residents who cannot fly from the United States because they are on the so-called "no-fly list" will finally have their case heard by a federal appeals court Friday.

The two-year-old suit claims the plaintiffs, who include two retired U.S. military veterans once stranded in Egypt and Colombia, have been unconstitutionally barred from flying without being told why or provided a meaningful chance to clear their names.

"A secret list that deprives people of the right to fly and places them into effective exile without any opportunity to object is both un-American and unconstitutional," ACLU attorney Ben Wizner said in a statement.

U.S. District Judge Anna Brown of Portland sided with the government last year, ruling the Department of Homeland Security's redress program, known as the Traveler Redress Inquiry Program, cannot be challenged in the lower federal courts, only in the appellate courts.

"The court also concludes any 'order' through DHS TRIP that might cause the names of any or all plaintiffs to remain on or to be removed from any no-fly list would have to be issued by TSA pursuant to § 46110(a). Accordingly, this court does not have jurisdiction to provide the relief plaintiffs seek in their second amended complaint," Brown wrote.

The ACLU's appeal will be heard by the 9th U.S. Circuit Court of Appeals in Portland on Friday.

The plaintiffs include Raymond Early Knaeble, a U.S. citizen once stuck in Colombia; Samir Mohamed Ahmed Mohamed, Abdullatif Muthanna, Nagib Ali Ghaleb, three Americans prevented once from flying to the United States from Yemen; and Abraheim Mashal, a retired Marine prevented from flying from Illinois.

The ACLU said its clients were provided one-time waivers to fly to the United States, although the government maintains they are too dangerous to fly.

Those who figure out they have been put on the no-fly list or the selectee list (which subjects travelers to patdowns and increased scrutiny) may apply to be removed, but have no right to see the evidence used against them or to have a hearing.

In 2011, Gulet Mohammed, a teenage American traveling abroad, accused FBI agents of using the no-fly list as a way to compel him to talk about his travels. When he refused, he was then tortured in a Kuwaiti prison, Mohammed said.

The ACLU will have to contend with a 2006 ruling from the 9th Circuit Court of Appeals which rejected a challenge to the government's ID policy for air travel on the grounds that there's no constitutional right to fly. While the court found there is a constitutional right to travel, the justices argued that there are other means of traveling in the U.S. other than by plane.

The court will have to decide if that logic holds in a case involving Americans' rights to return to their home country.

The no-fly list, which includes both citizens and foreigners, increased in size from 10,000 to 21,000 names last year, after the government relaxed the requirements for being put on the list in 2010.

In February, the 9th Circuit revived a Malaysian woman's legal fight against the no-fly list, ruling she may challenge her two-hour detention on allegations she was wrongly singled out as a suspected terrorist at San Francisco International Airport. That case, brought by Rahinah Ibrahim, questions how far the law stretches when it comes to detaining watchlisted persons in U.S. airports.