WASHINGTON – Detail by painful detail, the CIA is coming to grips with one of the most devastating episodes in its history, a botched cloak-and-dagger flight into China that stole two decades of freedom from a pair of fresh-faced American operatives and cost the lives of their two pilots.

In opening up about the 1952 debacle, the CIA is finding ways to use it as a teaching tool. Mistakes of the past can serve as cautionary tales for today's spies and paramilitary officers taking on al-Qaida and other terrorist targets.

At the center of the story are two eager CIA paramilitary officers on their first overseas assignment, John T. Downey of New Britain, Conn., and Richard G. Fecteau, of Lynn, Mass., whose plane was shot from the night sky in a Chinese ambush.

The mission was quickly smothered in U.S. government denials, sealed in official secrecy and consigned to the darkest corner of the spy agency's vault of unpleasant affairs.

Downey was the youngest of the four. At 22, with one year of CIA service, he was destined to spend the next 20 years, three months and 14 days in Chinese prisons. His CIA partner, Fecteau, was 25. He was behind bars for 19 years and 14 days.

Both survived. Their pilots, Robert C. Snoddy, 31, a native of Roseburg, Ore., and 29-year-old Norman A. Schwartz of Louisville, Ky., did not.

Bits and pieces of the story surfaced over the years. But the lid was largely intact until a series of disclosures — some required of the CIA, some not — revealed a tale of tragedy, miscalculation, misery and personal triumph, as well as the agency's misplaced confidence it could manipulate events in China.

Three years ago, the CIA declassified an internal history of the affair. Now it's hired a filmmaker to produce an hourlong documentary. The CIA does not plan to release the film publicly. But the agency premiered it for employees on Tuesday at its Langley, Va., headquarters, and an AP reporter attended.

Downey and Fecteau declined through CIA officials to be interviewed for this story. They attended the film screening and were flooded with applause and agency autograph seekers.

Their tale forms part of the backdrop to today's uneasy U.S.-China relationship, especially Beijing's anger over American military support for China's anti-communist rivals on Taiwan.

In the early years of the Cold War, the CIA had a rudimentary paramilitary force — those with specialized skills to conduct high-risk, behind-the-lines operations.

Downey and Fecteau were assigned to a covert program called "Third Force," intended to create a resistance network. Small teams of noncommunist Chinese exiles were airdropped into the Manchuria area of China to link up with disaffected communist generals.

The goal was to destabilize Mao Zedong's new government and distract it from the Korean War, which Chinese forces had entered two years earlier.

The plan failed — badly.

"The CIA had been `had,'" the late James Lilley, who helped train agent teams for insertion into China, wrote in his 2004 memoir, "China Hands." There were no dissident communist Chinese generals to be found, and the Chinese on Taiwan and Hong Kong who sold the idea turned out to be swindlers, Lilley wrote.

"The whole program smacked of amateurism," CIA historian Nicholas Dujmovic says.

Donald Gregg, who came into the CIA with Downey in 1951 and had dinner with him the night before his ill-fated flight, faults those in the CIA who oversold the program.

"That was a wild and woolly, swashbuckling time in the agency's history," Gregg said in an interview. "There was pressure from presidents for regime change here and there, and it was a very damaging time."

On Nov. 29, 1952, above the foothills of the Changbai mountains, Downey and Fecteau flew into Chinese air space in an unarmed C-47 Skytrain. They planned to swoop low over a rendezvous point marked with three small bonfires and use a tail hook to pick up a Chinese agent off the ground without landing. Downey was to reel in the agent with a winch aboard the plane.

As they descended, the sky suddenly exploded in bursts of gunfire. It was a Chinese ambush. The agent had betrayed the Americans, luring them by promising to provide important documents from a dissident leader.

After the C-47 slammed through a grove of trees, the cockpit burst into flames and skidded to a halt near the village of Sandao.

Downey and Fecteau, stunned and bruised but alive, were captured on the spot. They were hauled off to prison — first in the city of Mukden, then in Beijing — interrogated and isolated in separate cells. Each spent long stretches in solitary confinement, alone with their fears.

It was an intelligence bonanza for the Chinese. Both Americans, after a psychological battering, spilled the beans, to varying degrees.

Here lay one of the lessons: Agency officers with close links to a covert action program should not fly on such missions.

Another blunder: At a CIA base on the Pacific island of Saipan, the Chinese agent teams lived and trained together, inevitably learning of each other's missions. So the capture of one team risked compromising the rest.

Also, Downey was well known to the Chinese operatives because he trained them. When Downey was captured, a Chinese security officer pointed at him and said in English, "You are Jack. Your future is very dark."

For two years, until China announced that Downey and Fecteau had been convicted of espionage and sentenced — Fecteau for 20 years, Downey for life — neither the CIA nor the men's families knew their fate. The families received letters in December 1953 saying the two men were "presumed dead."

The CIA concocted a cover story, telling the families that the four had gone missing on a routine commercial flight from Korea to Japan on Dec. 3, four days after the shootdown.

After China announced that Downey and Fecteau were being held as spies, Washington publicly denied it, claiming they were civilian employees of the Army.

China did not mention Snoddy and Schwartz until 1975, when officials told President Gerald R. Ford the missing pilots had been found dead and "badly scorched" at the crash site, and that it would be impossible to locate their remains.

Fecteau was released by China in December 1971 and Downey in March 1973, shortly after President Richard Nixon publicly acknowledged Downey's CIA connection.

Both said after their return that to cope with their confinement they stuck strictly to a daily schedule.

Downey, for example, said he would rise each morning and begin a series of activities in his cell: calisthenics, cleaning, eating, reading, listening to the radio and reviewing an occasional package of letters, books and magazines. Fecteau had a similar approach but varied his routine by the day of the week.

Remarkably, once home they resumed normal lives. Downey earned a law degree from Harvard and became a judge. Fecteau returned to his alma mater, Boston University, as assistant athletic director.

The pilots, Snoddy and Schwartz, were not CIA officers but flew missions as employees of Civil Air Transport, an airline secretly purchased by the CIA in late 1949 to support its covert operations in East Asia.

In June 2004 a Pentagon search team, with authorization by China, excavated the crash site and found remains later identified as Snoddy's. Schwartz's remains were not found.

Downey and Fecteau have said little publicly. But intriguing details about their experience were revealed by Dujmovic, based on still-secret agency files. His 2006 account was declassified in three stages the following year.

Dujmovic wrote that the CIA unit chief who approved the mission apparently made crucial misjudgments for which he was never held to account. For starters, the unit chief ignored a warning that the Chinese agent team — codenamed STAROMA — had been compromised shortly after it arrived in Manchuria.

The CIA historian says Downey told a debriefer after his release that he felt no bitterness toward his CIA boss.

"I felt for him," Downey said. "It turned out to be such a goddamned disaster from his point of view."