When does an MEL category day countdown begin?

• A. The day of write up
• B. The day after write up
• C. The day after maintenance is completed
• D. The next calendar day

Answer: (B)

The countdown for an MEL category begins when the fault is written up in the MEL/logbook. The time window starts the day after that write-up is created, marking the moment the item becomes inoperative and the allowable remediation period begins. It isn’t started on the same day as the write-up, and it isn’t tied to waiting until after maintenance is completed. This rule keeps the clock aligned with the documented inoperative status and gives the crew a full, clear window to address the fault.