The deadliest aviation accident in Thailand's history and the Boeing 767's first fatal incident, killing all 223 aboard due to an uncommanded thrust reverser deployment.
Key Facts
- Date
- 26 May 1991
- Total fatalities
- 223 (213 passengers, 10 crew)
- Aircraft type
- Boeing 767-300ER
- Route
- Hong Kong – Bangkok – Vienna
- Cause
- Uncommanded thrust reverser deployment, No. 1 engine
- Record
- Deadliest Boeing 767 accident in history
By the Numbers
Location
Cause → Event → Consequence
During the climb phase after departing Bangkok, the thrust reverser on the No. 1 engine deployed without command. This unexpected reversal of engine thrust created extreme aerodynamic forces the crew could not overcome, leading to a catastrophic loss of control.
On 26 May 1991, Lauda Air Flight 004 entered an aerodynamic stall and uncontrolled dive following the uncommanded thrust reverser deployment, resulting in in-flight structural breakup over Thailand. All 213 passengers and 10 crew members perished.
The accident prompted Boeing and aviation regulators to review thrust reverser safety systems on the 767 fleet. Lauda Air founder Niki Lauda personally participated in the investigation. The crash remains the deadliest aviation disaster in Thailand's history and the deadliest involving a Boeing 767.