But in November 1954, the Chinese government announced that the two were alive and serving sentences as convicted C.I.A. spies. Mr. Fecteau was sentenced to 20 years and Mr. Downey to life.

They remained imprisoned until relations between China and the United States warmed in the early 1970s, culminating with President Richard M. Nixon’s groundbreaking visit in 1972. Mr. Fecteau was released in late 1971, after serving 19 years and 14 days.

Nixon personally intervened to secure Mr. Downey’s release after the prisoner’s mother, who had visited China five times to plead on her son’s behalf, suffered a severe stroke. He was freed on March 13, 1973, shortly after the United States acknowledged for the first time that Mr. Downey had been connected to the C.I.A. On his release — 20 years, three months and 14 days after his plane had been shot down — China said he had “confessed to his crimes.”

Because they were seized during the Korean War, Mr. Downey and Mr. Fecteau have long been described as prisoners of war, though they were not uniformed service members. Col. Floyd Thompson, who was imprisoned for nearly nine years during the Vietnam War, is America’s longest-serving uniformed serviceman taken prisoner.

Last year, John O. Brennan, director of the C.I.A., presented Mr. Downey and Mr. Fecteau with the Distinguished Intelligence Cross, the agency’s highest award for valor.

“It has been 61 years since Dick and Jack took to the skies over North Korea and China during the Korean War,” Mr. Brennan said, “and their ordeal remains among the most compelling accounts of courage, resolve and endurance in the history of our agency.” In 2010, the C.I.A. commissioned a documentary film on the men’s experiences that was intended for internal training purposes. The movie, “Extraordinary Fidelity,” has since been released to the public and is available online.

Mr. Downey, who lived in New Haven for many years, is survived by his wife of 40 years, the former Audrey Lee; his son, Jack; and his brother, William.