What happened
On July 6, 2013, Asiana Airlines flight 214, a Boeing 777-20 andER with registration HL7742, was performing a visual approach to runway 28L at San Francisco International Airport. During the descent, the aircraft drifted below the intended visual glidepath and struck a seawall located near the airfield. The impact caused significant damage to the aircraft, which was ultimately destroyed. The accident resulted in 3 fatalities and numerous injuries, with 40 passengers and 8 flight attendants sustaining serious injuries.
The investigation
The investigation focused on the flight crew's management of the approach and the aircraft's automated systems. Investigators examined the flight data, cockpit voice recordings, and the performance of the aircraft's autothrottle and flight director systems. The inquiry also looked into the adequacy of the aircraft's low-speed alerting mechanisms and the crew's adherence to standard operating procedures during the visual approach. Additionally, the investigation reviewed the emergency response, including the effectiveness of the airport's rescue and firefighting operations and the performance of the aircraft's evacuation slides.
Findings
Technical analysis revealed that the Boeing 777-200ER failed to provide adequate airspeed protection in certain automation modes, specifically when the autothrottle was in the HOLD mode. The investigation determined that the aircraft's low-speed alert was insufficient; rather than a high-priority warning, the system issued a general caution chime that was indistinguishable from many other non-critical alerts. This lack of a distinct, urgent signal contributed to a delayed crew response. Furthermore, inconsistencies in the automation behavior and the lack of a direct, voice-based airspeed alert prevented the crew from identifying and correcting the decaying airspeed in time to execute a successful go-around.