A member of the CIA-trained Black Cat Squadron, he flew the American U-2 reconnaissance aircraft to spy on China's nuclear program.

Chang was released from custody in 1969 and sent back to his hometown, in 1982 he was able to leave the mainland but was not granted permission to return to Taiwan until 1990, living the interim years in the United States.

Chang's mother fled the city with the children and trekked across China for more than a year, eventually arriving in the wartime capital Chongqing in 1939.

To reach the project sites located deep inland in Northwest China, ROC pilots were trained by the Central Intelligence Agency in the United States to fly the Lockheed U-2 high-altitude reconnaissance aircraft.

[4] When he flew over Baotou, Inner Mongolia,[5] his plane was shot down by a surface-to-air missile launched by the 1st Battalion of the People's Liberation Army Air Force under the command of Wang Lin.

[6] In April 1965, four U-2 aircraft were shot down by China, including the U-2C piloted by Chang, were put on display at the Military Museum of the Chinese People's Revolution in Beijing.

[6] Yang Shiju (楊世駒), a former commander of the Black Cat Squadron, contacted the CIA, which settled the duo in the United States.

[6] Neither pilot received a medal from the CIA, but their shoot-down had a major impact on the agency and the US Air Force, which began to prioritize the development of pilotless drones at Area 51.