A Wolters Kluwer analysis argues that aviation safety investigators should substitute the Human Factors Analysis and Classification System (HFACS) for the default "pilot error" finding that closes many final reports.

The piece, headlined "From 'pilot error' to root cause: applying HFACS in aviation safety investigations," frames the methodology as a corrective to probes that stop at the cockpit without naming the supervisory, organizational and environmental contributors behind a loss-of-control event, runway excursion or controlled-flight-into-terrain accident.

What is HFACS and what does it add?

HFACS is a taxonomy that organizes human contributors to an accident across four layers: unsafe acts (front-line crew behavior), preconditions for unsafe acts (fatigue, physiological factors, mental state, crew resource management), unsafe supervision (pairing, training adequacy, scheduling) and organizational influences (safety culture, maintenance resourcing, procedural design). The framework was published in the late 1990s and early 2000s by U.S. researchers and is now used by military accident boards, with variations adopted by some civil investigators.

Applied systematically, the taxonomy forces the record to capture supervisory and organizational factors that a single "pilot error" line on a findings page tends to obscure.

Why does the shorthand persist?

The phrase "pilot error" remains attractive to investigators because it closes a case file quickly and matches the public's intuitive model of who was flying at the moment a chain broke. It also assigns responsibility cleanly, which appeals to prosecutors in criminal cases arising from fatal accidents and to liability counsel representing survivors' estates.

The shorthand carries direct cost and capacity consequences for airlines and lessors, however. A conclusion that names the crew alone does not trigger the simulator-recurrent training updates, scheduling-rest changes or safety-management-system amendments that a layered root-cause finding can justify. Insurers and operators cannot allocate reserves against the corrective line items a structured report would identify.

Crew-labor representatives also routinely challenge findings the union considers unjustly localized to line operators. A taxonomy-driven report distributes findings across four layers, narrowing the surface available for grievance arbitration and reducing the legal exposure that follows an overly flat determination.

What changes for investigators in practice?

For an NTSB-style investigator, the practical shift involves substituting structured taxonomy for narrative shorthand in the findings section. Investigators still document crew actions, but the report must also walk the chain back through training quality, fatigue exposure, supervision and the safety culture of the operating certificate holder.

The framework's principal value, the analysis suggests, is that it gives accident boards a shared vocabulary across cases. Comparable taxonomies let regulators and operators benchmark their findings against peer investigations and track the prevalence of specific layers — fatigue, procedure design, organizational slack — across a fleet over a year.

HFACS also lets the same investigator code multiple contributors without elevating any single factor to a probable-cause determination. That distinction matters in jurisdictions where probable-cause language triggers liability for airlines, manufacturers and pilots in tort claims.

What to watch

Whether HFACS or a close derivative becomes a mandatory checklist in civil final reports will depend on regulators' willingness to codify a structured human-factors taxonomy inside the published findings. The next round of EASA and FAA guidance on human-factors methodology — expected to consolidate post-2010s recommendations — will indicate how far that shift extends. Until then, the article implies, HFACS remains an option for safety-action plans rather than an enforced line item on the findings page.