As one of my former bosses often observed, for many years the global approach to aviation accident inves­tigation was find, fix, and fly. This approach was primarily directed to issues with the machine and/or the weather, two pieces of what turns out to be a three-part puzzle. It’s pretty easy to find and fix problems with the machine. Technology (e.g., radar, stormscope) and rules (e.g., stay away from thunderstorms!) could fix — sort of — accidents involving weather. The third piece, the human being, was not exactly ignored. But because it’s a lot harder even to see, much less under­stand, the reasons for certain human actions and behaviors, the vague “pilot error” term was a catch-all. 

The more we learn, though, the more we know how much we still need to learn about pilot error. It may be easy to see what the pilot actually did, but the why and the how are key to prevention. That’s where the human factors (HF) discipline comes in. 

Investigating HF 

To learn more about what these specialists do, we queried Dr. Sabrina Woods, a frequent FAA Safety Brief­ing contributor who now works as a Human Factors Analyst in the Accident Investigation Division of the FAA’s Office of Accident Investigation and Prevention (AVP). 

“The International Civil Aviation Organization’s Manual of Aircraft Accident and Incident Investigation details how human factors issues should be investigated post-accident,” she noted. The manual lists the objec­tives of human factors investigation as: (1) determining how breakdowns in human performance may have caused or contributed to an occur­rence; (2) identifying safety hazards related to limitations in human per­formance; and (3) identifying ways to eliminate or reduce the consequences of faulty human actions or decisions. 

HF work encompasses the “domains” of human, machine, and environment — the standard ingre­dients in the recipe for any accident or incident. Any human performance investigation must consider six differ­ent fields, keeping in mind that, like a kaleidoscope, these factors interact and combine in myriad ways. The elements that create any given situation include: 

• Behavioral: 72-hour history, oper­ator’s behavior, life habit patterns, and life events. 
• Medical: general health, sensory acuity, drug/alcohol ingestion, and fatigue. 
• Operational: training, experience, habit patterns, operational proce­dures, company policies, culture.
• Task: information, perception, task components, workload, saturation, stimulus, time. 
• Equipment Design: workspace, man-machine interface, instrument display/design, controls layout and design, seat design/configuration, alerting systems. 
• Environmental: external conditions, internal conditions, illumination, noise, vibration. 

At the Scene 

By law, the National Transportation Safety Board (NTSB) is responsi­ble for determining probable cause for any accident or incident in the United States. Also by law, the FAA participates in the investigation. The FAA team includes HF experts like Sabrina. “My primary job is to help the lead FAA investigator determine and analyze the human factors issues in the accident or incident,” she notes. “I might launch with the ‘go team,’ or help with transcriptions and witness interviews.” 

The bulk of the work occurs after the on-site investigation concludes. “HF experts develop a human perfor­mance assessment so as to improve the safety risk management and mitigation process,” says Sabrina. Other duties include providing sub­ject matter expertise on HF-related safety recommendations, and leading human performance/human factors data analysis. 

“Strong communication skills are a must,” she adds, to be an effective interface with fellow HF specialists not just in the FAA, but also in the NTSB, with major industry stake­holders, and global counterparts in the HF discipline. 

We all benefit from the work that dedicated Human Factors Investiga­tors do to improve aviation safety. (FAA Safety Briefing – Jul/Aug 2020)