Which component is described as permanent?

• A. Probes and sensors (Permanent)
• B. Level 1 electric anti icing
• C. Main and Emergency Battery
• D. Spring tab

Answer: (A)

The main idea here is identifying parts that are treated as long-life, non-consumable items in maintenance terms. Probes and sensors are considered permanent because they serve as the continuous sensing interface for the aircraft’s systems and are designed for extended service life. They’re installed during manufacture and aren’t routinely replaced like consumables; instead, they’re inspected and calibrated as part of ongoing maintenance, and only swapped out if they fail or are damaged.

In contrast, the other items are not viewed as permanent. A Level 1 electric anti-icing component is part of a system that can fail and be replaced, not a long-life, fixed item. Batteries are life-limited and replaced on a schedule or after failure. A spring tab is a mechanical device that can wear or fail and typically isn’t kept as a permanent, fixed element.