The small airport that houses what some here call Smithfield’s “dirty secret” lies just beyond the town’s outskirts, where tobacco warehouses and car dealerships give way to pine forests and then, abruptly, an imposing 10-foot-high fence.

Inside, in a metal hangar with its own security, is the headquarters of Aero Contractors Ltd., a private aviation company whose ties to the CIA have long inspired local speculation and gossip. Newspaper investigations and books have linked the firm’s planes to secret abductions, waterboardings and more, usually eliciting the same mute response from the occupant of Hangar No. 3.

These days, Aero’s jets are seldom seen in public, and the controversy over the CIA’s “extraordinary rendition” program — in which captured terrorist suspects were secretly transported to another country for interrogation — has vanished from the headlines in most of the country.

But not so here, where Aero’s operations have spawned a dogged opposition movement in its otherwise conservative, fiercely patriotic back yard. The protests continue to gather steam after six years, despite counter-demonstrations and occasional threats, and amid uncertainty over whether Aero is still involved in what critics alleged was a “torture taxi” business.

“I don’t want to live in a country that acts this way,” said Julia Elsee, 87, who bundled up in a pink scarf for a protest at the Johnston County Airport on a recent chilly afternoon.

The most controversial interrogation and detention practices ended in 2006, and further limits were imposed by the Obama administration, which has prioritized killing suspected terrorists over capturing them. Yet, 10 years after the first “high-value” detainee was hooded and forced into a CIA plane, Aero’s presence remains for opponents a powerful symbol: a rare, visible reminder of what they view as a uniquely shameful chapter in America’s history.

Such views are far from universal here. Many in this central North Carolina community of 13,000 say they’re proud of the contributions that Aero may have made to the fight against al-Qaeda. Local politicians are only too happy to count Aero, with its fleet of planes and a workforce that protesters estimate to number as many as 150 employees, as part of the tax base in a community that can no longer rely on tobacco.

“You’re barking up the wrong tree,” Allen Mims Jr., chairman of Johnston County’s Board of Commissioners, told Aero opponents who asked at a recent hearing for a county probe into the company’s practices.

The protesters, who want to see the company investigated, censured and possibly shut down, likewise have made little headway in gaining public support from the state’s Democratic administration, or from most of the state’s congressional representatives, or from the Obama administration, which has banned waterboarding but declined to broadly investigate the CIA’s interrogation program.

To the disappointment of human rights groups, the White House has said it will continue to permit extraordinary renditions under certain conditions.

Yet, the protests continue, propelled by housewives, Sunday school teachers, real estate agents and grandmothers. A rally in January drew about 50 people to the airport, and roughly the same number attended a vigil near the state capitol in Raleigh.

At the Smithfield protest, they carried signs that read “Crime Scene,” “No More,” and “Who Would Jesus Torture?” They displayed the battered visage of a man believed to be one of Aero’s former passengers. And they cheered when one speaker, the chaplain of nearby Duke University’s campus chapel, called for eliminating a moral blight that “rots our country’s heart.”

“It is time to say this is wrong,” said the chaplain, the Rev. Sam Wells, gesturing toward the blue hangar at the far end of the tarmac.

Aero officials declined invitations to attend the rally or speak to reporters. The airport management’s only response was to position an employee near the door of the tiny brick terminal to study the protesters through binoculars.

“We don’t comment on these things,” an Aero receptionist said.

‘Mayberry cloak-and-dagger’

Allyson Caison, 51, a real estate broker and mother of two, remembers the first time she heard about the company she now knows as Aero. The terrorist attacks of Sept. 11, 2001, were still years away, and the whispers about a clandestine air service at the tiny Johnston County Airport seemed more exciting than sinister.

“It was a kind of ‘Mayberry cloak-and-dagger,’ ” said Caison, who recalled how parents buzzed about the airport’s mysterious tenant during Boy Scout meetings in the mid-1990s.

Like many in the county, she was fascinated when news stories in 2005 first linked the contractor to the CIA’s extraordinary renditions. That practice also was newly coming to light, along with tales of secret prisons and harsh interrogation methods that included waterboarding, in which detainees were made to believe they were drowning in order to coerce information from them. But as she read the stories, Caison was hit by a jarring realization: She was personally acquainted with several of the managers of the company now publicly linked to the CIA’s abduction of terrorist suspects overseas.

“Holy cow, I know these people,” she recalled thinking. “I’ve baked gingerbread houses for a couple of them.”

The news reports described what was then a 20-year relationship between the CIA and Aero, a company founded by James Rhyne, a former chief pilot for Air America, the former CIA-run company that flew clandestine missions for the agency during the Vietnam War. After Sept. 11, when the agency needed transportation help in dealing with newly detained terrorist suspects from Afghanistan and Pakistan, Aero already had a record of supporting the agency’s complex international missions with complete discretion. Its small jets and experienced pilots could be summoned quickly for missions anywhere in the world, free of the risk of being of directly traced to the spy agency.

Beginning in early 2002, those missions reportedly included shuttling between the cities of South Asia, the Middle East and North Africa, where scores of young Muslims were being questioned on suspicion of links to al-Qaeda. Human rights groups allege that the CIA used Aero’s planes to pick up detainees in Afghanistan, Iraq and Pakistan and transport them either to the CIA’s so-called black-site prisons or to the custody of foreign governments for interrogation and imprisonment.

Flight records for Aero planes show regular travel between those countries between 2002 and 2006, as well as stops at a regional airport in eastern Poland, where the CIA operated one of its secret interrogation centers.

Agency officials have repeatedly defended the practice of extraordinary rendition as legal — authorized in presidential directives by a succession of U.S. administrations as an effective tool for dealing with suspected terrorists. Both the George W. Bush White House and the Obama administration have denied knowingly sending detainees to countries to be tortured. The CIA has declined to discuss its relationship, if any, with Aero, and also declined to comment for this story.

In addition to calls made to Aero’s headquarters, e-mails sent to Aero corporate officials were not acknowledged.

Mims, the county commissioner, said in an interview that the company has been an upstanding local corporate citizen for more than two decades. He said local officials knew the company operated a charter service but had no direct knowledge — and no jurisdiction — with regard to business it may conduct overseas.

Mims suggested that he would not be disappointed to learn that the company had helped the CIA in its pursuit of suspected terrorists. Even if the stories are true, he said, Aero was only the transportation service.

“It’s not much different from hiring a taxicab,” he said. “I’d rather that the CIA do it that way than put a terrorist on a Delta flight and endanger the rest of us.”

To Caison, it wasn’t the company’s link to the CIA that was troubling. Rather, it was the idea that planes from Smithfield were being used to deliver young men of roughly her sons’ age to foreign prisons where they could be tortured, in a system outside any of the usual norms of U.S. justice. To her, torture was a moral red line, a tactic used by despots and by terrorists themselves, but not by a democracy with a predominantly Christian population.

“Our country is better than this,” she said. “We’re supposed to be a beacon of light.”

Caison shared her views at church, thinking that her fellow Methodists would be as outraged as she was. To her amazement, few were.

“The usual response was: ‘Those people are terrorists,’ ” she recalled. “Even if a few innocent people got caught up in it, it was okay if it kept our country safe.”

Caison left her church and eventually found herself participating in the airport protests that were then getting underway. It was an unfamiliar role and a costly one: Her real estate business suffered, and some friends and neighbors began avoiding her. Caison’s two sons were mocked by classmates, and an essay in the local newspaper derided her family as “America-haters.” She received threatening letters, and once, during a 2007 protest, was menaced by a counter-protester, a tattooed motorcyclist who screamed profanities at her, his crimson face inches from her own.

She stood her ground. But five years later, the memory still rattles her.

“Torture is not the issue I would have picked,” Caison said recently as she drove through her neighborhood and past the pink-and-white wood-frame house where she and her husband raised their two sons. “But this happened in my back yard. I live literally in the flight path.”

A detainee’s story

Abou el-Kassim Britel has been in that flight path, too, but his perspective is markedly different. He recalls lying on his back on the floor of what he believes was an Aero jet, wearing diapers and handcuffs as men with American accents barked orders at him.

“I lay like that for six hours, maybe more,” said Britel, a Moroccan-born Italian citizen, describing in an interview a harrowing late-night journey from Pakistan to Morocco in 2002. “When I tried to move to get comfortable, the man sitting near me would hit me.”

A decade later, Britel, now free and living in Italy, has become intimately connected to the cause of the North Carolina activists, none of whom he has met. His American correspondents sometimes carry posters of Britel’s face in their rallies, and they read letters from Britel or his Italian wife at public hearings.

Over the months, he has become both a human face of the rendition program and, short of indictments, a reason for the protesters to keep on campaigning.

“We’re looking for a measure of accountability,” said Josh McIntyre, an administrative worker at a local college and a founding member of the North Carolina group that calls itself N.C. Stop Torture Now. “But we also want to say to these people as a society, ‘We’re sorry about what happened to you.’ ”

Britel, for one, isn’t holding his breath. While Italian courts have exonerated the former Arabic translator of links to terrorism, a U.S. judge, citing secrecy laws, dismissed a private lawsuit brought on behalf of Britel and other former detainees seeking damages from Aero.

“No one recognizes this injustice,” Britel said in the interview.

An affidavit prepared as part of his legal case lays out the basics. Britel, it says, was in Pakistan on business in March 2002 when Pakistani authorities arrested him, initially on immigration charges. After an interrogation, he was accused of being a “terrorist fighter” and subjected to abuses that he says included being hung by arms from the ceiling and beaten with a cricket bat. Britel said he suffered permanent hearing and vision damage because of the beatings.

After signing what the affidavit says was a false confession, Britel was handed over to Americans. On May 24, 2002, five men wearing black clothes and masks put him in diapers and whisked him to the airport.

“I was then dragged on board a small aircraft and forced on my back,” Britel said. Hours later he was in Morocco, where he remained imprisoned until he was released eight months later without having been charged. (He was later arrested by the Moroccans in connection with an unrelated offense; he was freed last year.)

Britel acknowledges that he could not have known who owned the plane. But flight records subsequently showed a privately owned Gulfstream V turbojet leaving Islamabad and arriving in Rabat on dates that matched with Britel’s account.

The jet’s identification numbers match those of a Gulfstream jet owned by Aero, according to a 70-page dossier on Aero’s alleged role in rendition flights, prepared by University of North Carolina law school faculty members and students on behalf of anti-torture activists.

The UNC report, issued last month, contends Aero “appears to have violated” international law by allegedly filing “dummy” flight plans to disguise routes and destinations while flying for the CIA. It also alleges that the company “aided in the kidnapping, extraordinary rendition, secret detention, and torture,” while operating under a state business permit and being subject to the state and federal laws.

The accusations were not new, but the North Carolina activists seized on its release to make a fresh pitch to state and county government officials. Members of the group recently delivered copies to officials from the governor’s office and state attorney general, who accepted them politely but made no promises.

More copies were distributed to a handful of reporters who attended the group’s rally at the airport. Christina Cowger, one of the protest’s leaders, hailed the report as a step toward what she hoped would be a formal investigation of Aero by the state.

“Good people must start doing the right thing, now,” Cowger told the crowd, speaking through a microphone wired to a small guitar amplifier.

As Cowger spoke, one of the private planes based at the airport taxied along the runway and halted at a point adjacent to the group’s makeshift podium. For several minutes the pilot gunned the engine, drowning out her words.