Which acronym expands to 'Inoperative'?

• A. IOE
• B. INOP
• C. IOR
• D. ICE

Answer: (B)

In aviation maintenance and flight operations, INOP is the shorthand used to mark that a piece of equipment or a system is not functioning and is not available for use until it’s repaired. This designation is essential for planning, dispatch, and safety because it clearly communicates to pilots and maintenance crews which items are out of service and must be considered when preparing a flight. If something is INOP, it may or may not be allowed to operate under a MEL (Minimum Equipment List) with certain limitations, but the key point is that it is not operational.

The other options don’t represent “Inoperative” in standard airline terminology. IOE is commonly used for Initial Operating Experience or other contexts, not to denote a nonfunctional item. IOR and ICE refer to different phrases (and contexts) such as Internal Combustion Engine or In Case of Emergency, none of which convey the specific maintenance status of being inoperative.