What is an airworthiness directive?

An airworthiness directive is a notification issued by aviation authorities that informs aircraft owners and operators about a known safety deficiency affecting a specific aircraft model or system. The purpose of an airworthiness directive is to ensure the continued safety and airworthiness of operated aircraft. When a safety issue is identified, the directive provides instructions on the required actions to address the deficiency, which can include maintenance, inspections, or modifications. This is critical in preventing accidents and ensuring that aircraft can be operated safely.

The other options do not correctly represent the nature of an airworthiness directive. Guidelines for pilot training focus on the skills and knowledge required for pilots, while a report on operational efficiency would address operational aspects rather than safety deficiencies. A regulation on passenger capacity pertains to the number of passengers an aircraft can legally carry, which is unrelated to airworthiness issues. Thus, option B distinctly captures the essence and purpose of an airworthiness directive in aviation safety management.