HFACS & HFIX for Aviation Safety Investigations

Most aviation incidents don't have a single cause — they have a chain of human factors failures that passed through every layer of an organization's defenses. The Human Factors Analysis and Classification System gives investigators a structured framework to trace that chain from the unsafe act at the surface all the way to the organizational influences at the root. Paired with the HFIX intervention matrix, it transforms findings into targeted solutions that actually reduce recurrence. This guide gives aviation safety professionals the tools, checklists, and application guidance to use both systems with confidence.

• Apply the HFACS four-level framework — unsafe acts, preconditions, unsafe supervision, and organizational influences — to classify human error systematically
• Use the Swiss Cheese Model to understand how multiple latent failures align to produce an aviation incident
• Conduct structured witness interviews using HFACS-aligned interview questions that surface human factors evidence
• Complete HFACS checklists to ensure consistent, comprehensive classification across investigations
• Map findings to the HFIX intervention matrix to select and plan targeted human factors interventions that address root causes