Define a Service Bulletin (SB) and its relevance to continuing airworthiness.

• A. An SB is a manufacturer-issued recommendation for modifications or inspections.
• B. An SB is a regulatory fine for noncompliance.
• C. An SB is a pilot's note for flight planning.
• D. An SB is an optional maintenance checklist.

Answer: (A)

A Service Bulletin is a manufacturer-issued recommendation for modifications or inspections aimed at improving safety and reliability based on new findings or observed service experience. It is a way for the maker to communicate potential issues and the best way to fix or prevent them, such as updated procedures, parts changes, or more frequent inspections.

In terms of continuing airworthiness, SBs matter because they guide maintenance programs on what actions should be considered or performed to keep the aircraft operating safely. Depending on the regulatory framework and how the SB is adopted, some SBs become mandatory through airworthiness directives or by being incorporated into the operator’s approved maintenance program. So the SB itself is advisory in origin, but its impact on ongoing airworthiness comes from how regulators and operators decide to implement the recommended actions.