In the Red Book instruction, which word completes the directive: The aircrew member reading the Red Book should first read the title to confirm the correct procedure?

• A. MUST
• B. SHALL
• C. SHOULD
• D. MAY

Answer: (B)

The important idea here is how directive language communicates obligation in safety-critical manuals. In aviation manuals like the Red Book, the word that conveys a mandatory action is used to require compliance. Completing the directive with shall makes it a non-negotiable step: the aircrew member must first read the title to confirm the correct procedure before proceeding. This ensures you’re applying the right procedure when several procedures can exist in the book, preventing misapplication due to mixing sections.

If the instruction used should, it would read as a recommendation rather than a strict requirement, which could be skipped. May would imply optional permission, and may not enforce the check at all. While must also signals a strong requirement, aviation standards commonly use shall to establish mandatory actions, so it aligns with the book’s established style and enforcement.