In ATR maintenance, the MEL specifies under what conditions an aircraft may continue operation when an item is inoperative.

• A. The Minimum Equipment List defines conditions for continued operation with inoperative items.
• B. The Mechanical Equipment List defines spare parts required.
• C. The Maximum Equipment List defines maximum permitted payload.
• D. The Mission Equipment List defines required sensors.

Answer: (A)

The Minimum Equipment List defines the conditions under which an aircraft may continue operation with an item inoperative. It translates the requirement for safe flight into dispatch rules, specifying which inoperative items may be tolerated, what limitations or procedures apply, and any time limits to repair. This is why it’s the best description: it directly states that the MEL establishes when you can fly with something not working and what constraints accompany that decision. The other documents don’t serve this purpose—the Mechanical Equipment List isn’t the standard dispatch tool for inoperative items, a Maximum Equipment List isn’t the governing document for such cases, and the Mission Equipment List is about equipment needed for a specific mission, not general airworthiness for flight operations.