Definition
A subparagraph of Title 14 of the Code of Federal Regulations (14 CFR) Part 91, section 91.213, which addresses the operation of an aircraft with inoperative instruments or equipment. Subparagraph (a)(5) specifies that, for aircraft operated under an approved Minimum Equipment List (MEL), a letter of authorization from the FAA permitting such operation must be carried aboard the aircraft and is considered a supplement to the airworthiness certificate.
Plain English
A specific FAA rule that says: if you're flying with an approved list of items that are allowed to be broken (an MEL), you must carry the FAA's written permission letter on board the aircraft.
Context Anchor
Seen when deciding whether a jet airplane may legally be flown with a piece of installed equipment not working.
Derivation
This is a regulatory address, not a normal word origin. “91” points to Part 91 operating rules, “91.213” points to the rule on inoperative instruments and equipment, and “(a)(5)” points to the fifth requirement in paragraph (a).
Why Pilots Care
Determines whether a jet can be legally dispatched with specific equipment inoperative without violating airworthiness rules.
Intuition Check
Do not read “section 91.213(a)(5)” as a general reference to maintenance paperwork. It points to one exact legal requirement: if you use the approved list to fly with equipment not working, you must follow the list’s limits and the FAA authorization.
Example Sentence 1
Before departure, the captain confirmed the section 91.213(a)(5) letter of authorization was in the aircraft documents binder along with the MEL.
Example Sentence 2
The captain checked section 91.213(a)(5) to verify the aircraft remained legal for the planned VFR leg despite the faulty gauge.