INOP is an aviation abbreviation used to indicate equipment status. What does INOP stand for?

• A. Not Operating
• B. Inoperative
• C. Inoperative Equipment
• D. Inoperative Condition

Answer: (B)

The main idea here is how INOP communicates equipment status in aviation. INOP is a shorthand used to indicate that a piece of equipment is not functioning and is out of service. The official expansion is simply Inoperative. This single-word status is used in maintenance logs, MELs, preflight checks, and crew communications to keep notes clear and concise about what is usable and what isn’t. While phrases like “Not Operating” or “Inoperative Equipment” convey the same idea, they aren’t the standard expansion of the abbreviation; INOP is specifically expanded as Inoperative.