Definition
A published altitude representing the highest altitude at which an aircraft may be operated on a Federal airway, jet route, area navigation low or high route, or other direct route for which an MEA is designated. This altitude limit is established to prevent navigation signal interference between facilities transmitting on the same frequency.
Plain English
The highest altitude you are allowed to fly while using a particular airway or route. Above this altitude, the navigation signals along that route can start overlapping with signals from other stations on the same frequency, which would make the route unreliable.
Context Anchor
Seen on instrument charts and in route planning when checking altitude limits for an airway, route segment, or airspace structure.
Derivation
‘Authorized’ comes from Latin auctor, meaning ‘originator’ or ‘one who grants permission.’ In this term it points to a permission boundary set by the FAA — not a physical limit of the aircraft, but the highest altitude permitted on that specific route.
Why Pilots Care
Keeps the aircraft within reliable navigation signal range and prevents loss of situational awareness during IFR flight.
Intuition Check
MAA does not mean the highest your aircraft can climb. It means the highest altitude officially published and allowed for that route segment or airspace structure.
Example Sentence 1
The MAA on that airway segment is 15,000 feet, so we filed for 14,000 to stay within the published limit.
Example Sentence 2
Approaching the MAA, the pilot began a descent to stay inside the authorized altitude for the next segment.