Definition
An unmanned aircraft weighing less than 55 pounds on takeoff, including everything that is on board or otherwise attached, together with its associated elements (such as the control station, data links, and any other components) required for the safe and efficient operation of the aircraft in the National Airspace System.
Plain English
A small drone — under 55 pounds fully loaded — plus all the gear on the ground and in the air that lets the operator fly it safely.
Context Anchor
You will see this term in FAA drone rules, airspace discussions, airport-area operations, and reports or advisories involving drone activity.
Derivation
Unmanned means no pilot is on board. System is the key word here — it is not just the drone itself, but the whole package: the aircraft, the controller, and the link between them. Calling it a system reminds you that a failure in any part (lost link, dead controller battery, software glitch) is a failure of the whole operation.
Why Pilots Care
Manned aircraft pilots must remain aware of sUAS operations to avoid mid-air conflicts and maintain safe separation.
Intuition Check
Do not read sUAS as just the drone in the air. In FAA use, it means the drone plus the equipment needed to operate it. Do not read unmanned as uncontrolled. It means there is no pilot on board the aircraft.
Example Sentence 1
The sUAS operator obtained airspace authorization before flying within five miles of the airport.
Example Sentence 2
Operators must register a Small Unmanned Aircraft System with the FAA prior to flight.