Definition
The deliberate duplication of critical data, data sources, or data pathways within a system so that if one source or path fails, another is available to provide the same information. In NextGen and avionics contexts, it refers to having multiple independent sources (such as GPS plus inertial reference, or dual receivers) supplying the same navigation, surveillance, or communication data.
Plain English
Having more than one source for the same important information, so if one source fails, another can take over without interruption.
Context Anchor
Seen in NextGen and instrument procedure discussions where aircraft, controllers, and automation depend on reliable position, route, weather, and traffic information.
Derivation
Redundancy comes from the Latin redundare, meaning 'to overflow' or 'to be more than enough.' In engineering, it kept the sense of 'more than the minimum needed' — extra capacity held in reserve. Applied to data, it means extra copies or sources of the same information beyond the single one strictly required.
Why Pilots Care
Ensures navigation and flight data remain reliable if a primary source fails, supporting safe decisions during instrument flight.
Intuition Check
Do not read redundancy as useless repetition here. In this context, data redundancy means planned backup information that helps the system remain reliable.
Example Sentence 1
The aircraft's navigation system uses data redundancy by combining GPS and inertial reference inputs, so a brief GPS dropout does not interrupt the displayed position.
Example Sentence 2
During an IFR approach the aircraft maintained accurate altitude data thanks to built-in data redundancy across its computers.