Which mandatory action must be taken regarding inoperative equipment listed in the MEL?

The correct action regarding inoperative equipment as listed in the Minimum Equipment List (MEL) is to deactivate and placard it. This means that the equipment which is not functioning should be disabled to prevent its use and clearly indicated with a placard that informs crew members and passengers of its inoperative status.

This procedure is crucial for maintaining safety and compliance with regulations. By placarding the inoperative equipment, it ensures that all personnel are aware of its status, preventing accidental use that could lead to operational issues or safety hazards. The MEL provides specific guidelines on how to handle various types of inoperative equipment, and following these guidelines allows the aircraft to be operated under certain conditions while ensuring safety is not compromised.

Repairing the equipment immediately is often impractical and unnecessary if the MEL allows for continued operation with the equipment inoperative. Similarly, notifying the FAA is not generally required unless specific conditions of the MEL state that such notification is needed. Removing the equipment from the aircraft may not be feasible or required under MEL guidelines, especially when the MEL permits operations with the inoperative items under specific conditions. Thus, deactivating and placarding the equipment aligns with the procedures set forth in the MEL for safe operations.