Investigation Summary
The accident occurred during a high-speed climbout at approximately 5,200 feet. The crew initially reported problems with the number 2 engine, though subsequent investigation confirmed the failure originated with the number 3 engine on the opposite wing. The detachment of the number 3 engine was catastrophic; as it broke free, it swung upward and outward, striking the number 4 engine and tearing it from its mounts. This left the aircraft with no power on the right side and significant aerodynamic damage to the right wing. The crew attempted to return to Taipei, but found the aircraft unresponsive to left-turn inputs. As they attempted a right-hand turn to compensate, the aircraft entered an uncontrollable descent and struck a hill at an altitude of 700 feet. The search for the number 3 engine and its pylon in the sea took several months, eventually confirming that the pylon midspar fittings had failed due to fatigue cracking that originated at an improper weld repair.
Final Conclusions
The investigation concluded that the primary cause was the in-flight separation of the number 3 engine pylon due to fatigue cracking. This cracking was initiated by an improper weld repair performed during maintenance. The investigation cited inadequate maintenance engineering oversight by China Airlines and deficient regulatory surveillance by the Taiwanese Civil Aeronautics Administration. The crash, along with the nearly identical El Al Flight 1862 accident ten months later, highlighted a critical design vulnerability in the Boeing 747 pylon attachment fittings.
Photographic Evidence (1)
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Crew Experience
Captain
Lin Chun-lung (林春隆), aged 48. Killed in the crash.
First Officer
Cheng Yan-bo (程延博), aged 37. Killed in the crash.
Flight Engineer
Zhan Jun-hui (詹俊輝), aged 46. Killed in the crash.
Systems & Failure Modes
Engine Pylon Midspar Fittings
Structural components that attach the engine pylon to the wing's front spar. Fatigue cracking in these fittings led to the structural failure and engine separation.
Pratt & Whitney JT9D-7R4G2
The four turbofan engines powering the aircraft. The detachment of the two right-side engines (No. 3 and No. 4) caused a total loss of control.
Interesting Facts
- 01The aircraft had accumulated 45,868 flight hours and 9,095 cycles at the time of the accident.
- 02The number 3 engine and pylon struck the number 4 engine during detachment, causing both to fall into the sea.
- 03The aircraft involved, B-198, was the same airframe hijacked to mainland China in 1986 (China Airlines Flight 334).
- 04The last A-check maintenance occurred just 8 days before the crash, with only 74 flight hours logged since.
- 05The crash site was located at an altitude of 700 feet (210m) on a hill near Wanli.
Safety Actions & Advisories
Boeing 747 Pylon Modifications
Following this accident and El Al Flight 1862, Boeing ordered structural pylon modifications to every Boeing 747 in service to prevent similar fatigue-induced engine separations.