Hawker Siddeley HS.121 Trident crash, Sep 13, 1971 (9 killed)
Hawker Siddeley HS.121 Trident accident on September 13, 1971 near Öndörkhaan Khentii, Mongolia with 9 fatalities.
- Date: September 13, 1971
- Aircraft: Hawker Siddeley HS.121 Trident
- Location: Öndörkhaan Khentii, Mongolia
- Fatalities: 9
- Phase of flight: En route
A Chinese Air Force Trident was taken from Shanhaiguan by nine officers who intended to defect. It crashed near Ondorkhaan in Mongolia and all nine occupants died, including Lin Biao. The cause is disputed between fuel exhaustion and a shootdown.