256
1971-SEP-13 · Near Öndörkhaan, Mongolian People's Republic

People's Liberation Army Air Force — Flight 256

A Hawker Siddeley Trident 1E carrying Lin Biao, the designated successor to Mao Zedong, crashed in eastern Mongolia while fleeing China following a failed political coup. All nine people on board were killed. The Chinese government officially attributed the crash to fuel starvation after a rushed departure, while Soviet medical experts who examined the site suggested the aircraft was in a controlled flight into terrain, possibly due to pilot error or fatigue. The incident remains one of the most significant political mysteries in the history of the People's Republic of China.

Aircraft
Hawker Siddeley Trident 1E
Registration
256
Phase
Cause
Other
Souls on Board
9
Fatalities
9
Origin → Dest
Qinhuangdao Shanhaiguan Airport, China → Irkutsk, Soviet Union (intended)
Report

Investigation Summary

The aircraft, a British-built Trident 1E, departed Shanhaiguan Airport in a highly irregular manner during the early hours of September 13, 1971. The flight was not authorized by the central leadership in Beijing. The pilot, Pan Jingyin, reportedly bypassed standard procedures by only waking three mechanics, deliberately leaving the navigator and radio operator behind in the rush to depart. According to official Chinese accounts, Lin Biao, his wife Ye Qun, and his son Lin Liguo boarded the plane in haste to escape arrest following the exposure of 'Project 571', a plot to assassinate Mao Zedong. The aircraft flew north toward the Soviet Union but crashed approximately 250 kilometers from the border. The wreckage was scattered over a wide area, and the bodies were severely burned, though later identified through dental records by Soviet investigators. The crash led to a massive purge of the Chinese military hierarchy and a fundamental shift in the Cultural Revolution's trajectory.

Final Conclusions

The official Chinese government verdict, finalized in 1981, concluded that Lin Biao died while fleeing as a counter-revolutionary. The technical cause of the crash was officially cited as fuel exhaustion resulting from the crew's inability to locate a suitable landing site in the dark after the aircraft ran low on fuel. However, alternative findings by Soviet investigators suggested the aircraft was under control until it struck the ground at a shallow angle, potentially during an attempted emergency landing or due to spatial disorientation.

Video Analysis

No video analysis linked for this case file yet.

Airframe & Maintenance

Last Major Check
1966 (Year of Manufacture)

Systems & Failure Modes

i

Fuel System

The Chinese government claimed the aircraft suffered fuel starvation, suggesting the rushed departure prevented adequate refueling for the flight to the USSR.

i

Navigation Equipment

The flight lacked a professional navigator, which likely contributed to the aircraft's erratic flight path and eventual crash in remote Mongolia.

Interesting Facts

  • 01The aircraft was one of several Tridents purchased by China from Pakistan International Airlines.
  • 02Lin Biao was officially Mao Zedong's successor at the time of the crash.
  • 03The crash site was located at coordinates 47°42′N 111°15′E.
  • 04The aircraft was traveling away from the Soviet Union at the moment of impact according to some 1994 scholarship.
  • 05No black box data was ever publicly released by the Chinese or Soviet governments.
  • 06The aircraft used the call sign 252 during its positioning flight to Beidaihe on the evening of September 12 to mimic a regular passenger flight.
  • 07The aircraft's Manufacturer Serial Number (MSN) was 2131.

Safety Actions & Advisories

Airspace Closure

Chinese airspace was closed for several days following the incident to prevent further unauthorized flights by military officials.

Known Controversies & Unanswered Questions

Disputed Flight Intent

Reference ↗

While the Chinese government claims Lin was fleeing to the USSR for asylum, 1994 scholarship suggested the plane was heading away from the Soviet border at the time of the crash.

Cause of Crash

Reference ↗

Official Chinese reports cite fuel starvation, but Soviet investigators and some Western scholars have suggested the plane may have been shot down or crashed during a forced landing attempt.

Location

Near Öndörkhaan, Mongolian People's Republic · 47.7000, 111.2500

Case File History

  1. New evidenceUpdated event timeline and findings.
  2. New evidenceUpdated investigation summary and findings.

Related Cases

Case ID · lin-biao-incident-1971Last updated · Filed

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