Mishap investigations involving Class A, B, and on-duty Class C mishaps require at least how many casual factors?

• A. Two
• B. One
• C. Three
• D. Zero

Answer: (B)

In mishap investigations for these classes, identifying at least one causal factor is essential. A causal factor is any condition or action that contributed to the mishap, whether it’s a human performance issue, a procedure flaw, equipment deficiency, or environmental condition. Finding at least one helps target corrective actions so recurrence is prevented.

You may uncover multiple contributing factors as the investigation digs deeper, but starting with a minimum of one ensures there’s a concrete area to address. Zero causal factors would leave no basis for corrective action, and requiring three would be unnecessarily prescriptive—the key point is the minimum is one, with more as needed by the findings. For example, discovering that maintenance procedures were inadequately defined points you toward revising those procedures, improving training, and enhancing oversight.