Definition
An FAA Advisory Circular that explains the minimum equipment requirements for general aviation aircraft operating under 14 CFR Part 91, including how to determine which inoperative instruments and equipment must be repaired, deactivated, or placarded before flight when the aircraft is not operated under an approved Minimum Equipment List (MEL).
Plain English
An FAA guidance document that tells general aviation pilots how to legally handle broken instruments or equipment on their aircraft when they don't have an approved Minimum Equipment List to follow.
Context Anchor
Seen when studying minimum equipment lists and operations with aircraft equipment that is not working.
Derivation
AC stands for 'Advisory Circular,' the FAA's standard format for non-regulatory guidance. The number '91-67' indicates the circular relates to 14 CFR Part 91 (general operating and flight rules), and '67' is its sequential number within that subject series.
Why Pilots Care
It helps pilots determine whether a flight can proceed legally and safely when certain instruments or equipment are not working.
Intuition Check
Do not read AC 91-67 as a regulation by itself. It is FAA guidance that explains how to apply the rules; the legal requirements come from the regulations and any approved aircraft documents.
Example Sentence 1
When the autopilot failed before a Part 91 flight, the pilot consulted AC 91-67 to confirm the aircraft could still be flown legally with the equipment placarded inoperative.
Example Sentence 2
AC 91-67 provides the conditions that must be met before departing with certain equipment listed as inoperative.