What did the declassified documents reveal?

Cold open. This is a declassified United States Air Force action memorandum concerning an S‑R‑71 overflight of Hainan Island on December thirty‑first, nineteen seventy‑four. The document is notable because it records a brief, inadvertent intrusion into People’s Republic of China airspace during a high‑altitude reconnaissance mission. The source is archived at the Black Vault, https://archive.org/download/us-china-intel-CI02052/CI02052djvu.txt. Provenance. The memorandum was released to the public through a Freedom of Information Act request filed with the United States Air Force. The Black Vault posted the declassified file on its website on an unspecified release date, citing the declassification authority of the United States Air Force. The document is reproduced here exactly as it appears in the original file. The document. SECRET SPOKE ACTION MEMORANDUM. United States Air Force, DORADO. Drafted: EA/PRCM – TSBrooks. Approved: EA – Mr. Habib. Subject: ACTION MEMO – S‑R‑71 Overflight of Hainan Island, December thirty‑first, nineteen seventy‑four. Your decision is requested on whether to inform the People’s Republic of China about the accidental overflight of Hainan Island on December thirty‑first. On December thirty‑first a giant‑scale S‑R‑71 mission out of Kadena developed a generator fault while approaching the western edge of Hainan Island. The aircraft aborted its primary flight plan, turned northward, and discovered a cloud cover that concealed its approach to the western edge of Hainan Island. Although the pilot promptly executed a sharp left turn, it is estimated that the aircraft overflew the island to a depth of about four miles. Total time over the island and its territorial waters was several seconds, occurring at zero four one zero Zulu on December thirty‑first (twenty‑three ten Eastern Standard Time on December thirtieth; twelve ten Hainan Time on December thirty‑first). After completing the turn, the aircraft proceeded south to a point below Da Nang, where it crossed to a refueling point in the South China Sea, then returned to Kadena. Indications are that People’s Republic of China radar tracking of flight in the North Tonkin Gulf probably detected the overflight of Hainan. The Chinese have not reacted publicly, nor do we anticipate a public response; their last public warning, unquote number four ninety‑seven, was issued in October nineteen seventy‑two in response to an overflight of the Paracel Islands. We understand it has not been our practice in the past to disclose individual overflight incidents

Why was this case declassified?

This material entered the public record through the U.S. declassification and Freedom of Information Act (FOIA) process. The originating source document is linked on this page so the citation chain is auditable.

Cold Open.

◆ BLUF — The short version

Cold open. This is a declassified United States Air Force action memorandum concerning an S‑R‑71 overflight of Hainan Island on December thirty‑first, nineteen seventy‑four. The document is notable because it records a brief, inadvertent intrusion into People’s Republic of China airspace during a high‑altitude reconnaissance mission.

Date: AUG 5 · 2026
Release: Declassified · U.S. public record (FOIA)
Source document: View the primary source document

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What was Cold Open. about?: Cold open. This is a declassified United States Air Force action memorandum concerning an S‑R‑71 overflight of Hainan Island on December thirty‑first, nineteen seventy‑four. The document is notable because it records a brief, inadvertent intrusion into People’s Republic of China airspace during a high‑altitude reconnaissance mission.
Why was this case declassified?: This material entered the public record through the U.S. declassification and Freedom of Information Act (FOIA) process. Storyflo narrates it directly from the public release.

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