Human Factors Analysis and Classification System (HFACS)

What is an aviation accident that involves human factors as a cause? How was the HFACS method used to classify human error? How could the accident be prevented or mitigated in the future?

The Human Factors Analysis and Classification System (HFACS) is a human error framework that was originally used to investigate and analyze human factors aspects of aviation. With this framework, investigators are able to systematically identify failures within an organization that leads to an accident. The goal of HFACS is not to point fingers; it is to understand the underlying factors that lead to an accident.

In July 2013, Asiana Airlines Flight 214 took off from Inchon International Airport (ICN) and crashed during the final approach into San Francisco International Airport (SFO). An instructor pilot was sitting in the right seat while a pilot undergoing training on the Boeing 777 was flying the plane from the left-hand seat. A month earlier, the instrument landing system's vertical guidance (glide slope) on Runway 28L at SFO had been taken out of service, and a NOTAM was issued. With the ILS out of service, a precision approach on runway 28L was not available. Without the glideslope, the pilots made a very unstable and high-speed approach. When they discovered that they were too low and too fast, they attempted to salvage the approach, but when that didn't work and they tried to go missed, it was already too late. A part of the landing gear struck a seawall and the plane spun out, crashing on the runway.

The NTSB determined that the missed approach should have been executed immediately. The NTSB also noted the following contributing factors to the crash: fatigue and a downgraded performance following a nearly 11-hour flight, inadequate monitoring, supervision, and instruction of the pilot flying the aircraft by the instructor pilot, inadequate pilot training for planning and executing visual approach landings, and the crew's non-standard communication and coordination regarding using the auto-throttle and autopilot flight director systems.

Civil aviation accidents are not due to isolated incidents; therefore, most can be prevented using HFACS. Throughout history, industry-wide change has only been brought on after disasters or after the loss of lives. The HFACS model presents the opportunity to proactively change this mindset. By using this systematic approach to hazard identification, safety risk data can be collected and studied without the need for an accident to occur. The findings of this accident emphasize the various organizational levels that serve a role in aviation accidents and especially highlight the role of the highest tiers of an organization in the safety process. By starting accident investigations at the top of an organization, the implementation of HFACS can prevent the culmination of hazards from trickling down to the lower levels. This study also highlights the necessity of practicing a proactive approach to safety, mitigating hazards within an organization before they can lead to disaster.

References

Finlay, M., Joshi, G. (2022). Asiana Airlines Flight 214: The Boeing 777's First Fatal Crash. Simple Flying. https://simpleflying.com/asiana-flight-214-crash-story/

SKYbrary Aviation. (2023). Human Factors Analysis and Classification System (HFACS). SKYbrary.com.

https://www.skybrary.aero/articles/human-factors-analysis-and-classification-system