MEL and CDL
Minimum Equipment Lists (MEL) and Configuration Deviation Lists (CDL)s are more common in airline and charter operations. However, new pilots are expected to have a working understanding of MELs and CDLs and generally understand how to apply them in the real world. Although it is not very common, some flight schools do use MELs and CDLs.
Lesson Notes
A Minimum Equipment List (MEL) is a list of items that can be broken without affecting airworthiness. Manufacturers publish Master Minimum Equipment Lists (MMEL), which operators use to create their own MEL, which must be approved by the FAA before it can be used operationally. An MEL will specify maintenance actions required by pilots and/or mechanics in order to satisfy the requirements of the MEL.
A Configuration Deviation List (CDL) is a list of configuration deviations that can be permitted. A common example in large transport category airplanes is a missing flap fairing or gear door. Such deviations only slightly impact performance, and do not reduce the level of safety.
You are unlikely to use an MEL or CDL while flying a light single or twin engine aircraft, but almost all career pilots will use MELs at some point.
Additional Resources
Flashcard Questions
What equipment is listed on the MEL? Is it broken equipment or working equipment?
What does MEL stand for?
Your flight club airplane has an MEL. You preflight the airplane and find that the parking brake is inoperative. You look in the MEL and discover that there is no MEL for the parking brake. The flight club says that because it is not required equipment per 91.205 that you can legally fly it. Are they correct?