Which statement about MEL or CDL is correct?

• A. MEL lists inoperative equipment allowed with restrictions; CDL lists configuration deviations that permit flight with limitations.
• B. MEL is minimum engine limit; CDL is cabin door limit.
• C. MEL is maximum efficient load; CDL is cabin density limit.
• D. MEL is maintenance event log; CDL is configuration data log.

Answer: (C)

The main concept is understanding what MEL and CDL actually govern. The Minimum Equipment List explains which inoperative equipment can be allowed for flight with specific restrictions after proper approval, so the aircraft can still dispatch safely. The Configuration Deviation List describes which configuration deviations are permitted for a flight, also with defined limitations, until the item is repaired. That makes the statement describing MEL as listing inoperative equipment allowed with restrictions and CDL as listing configuration deviations that permit flight with limitations the best fit. The other ideas—MEL referring to a maximum efficient load or CDL to cabin density, or mixing up maintenance logs with these lists—don’t reflect how MEL and CDL are used in practice.