UAS Foundations
This broad term describes any device used, intended to be used, or designed to be used for flight in the air.
Aircraft
This role refers to the person responsible for operating or directing the air vehicle during a mission.
Air Vehicle Operator (AVO)
This includes the non-aircraft resources required to prepare, maintain, transport, launch, recover, or sustain UAS operations.
Support Equipment
This measurement is the total weight of an aircraft at the moment it begins takeoff, including the aircraft, payload, fuel or batteries, and installed equipment.
Gross Takeoff Weight (GTOW)
This broad size designation commonly refers to UAS that occupy the range between small systems and large systems; exact mass limits depend on the classification standard being used.
Medium UAS
This system consists of a remotely piloted aircraft, its control station(s), the required command-and-control links, and other components necessary for operation.
Remotely Piloted Aircraft System (RPAS)
These qualified individuals manipulate flight controls or otherwise direct the flight of an RPA from a location outside the aircraft.
Remote Pilots
This term encompasses the physical, meteorological, operational, electromagnetic, and regulatory conditions in which a UAS operates.
Environment
This general classification commonly identifies lightweight unmanned aircraft that fall within the lowest-weight civil operational rules, such as the FAA framework for drones under 55 pounds.
Small UAS (sUAS)
This U.S. military classification organizes unmanned aircraft into five groups based primarily on factors such as weight, operating altitude, and airspeed.
Department of Defense weight category Group 1–5
This describes an aircraft or system capable of performing a flight-related task without real-time human intervention in its management.
Autonomous
This ground- or ship-based facility contains the equipment used by personnel to monitor and control an unmanned aircraft.
Control Station
These national governmental bodies regulate aviation safety, airworthiness, licensing, and operational rules within their jurisdictions.
Civil Aviation Authorities
This general term describes unmanned aircraft whose size, mass, capability, or operational complexity exceeds the limits normally associated with small UAS.
Large UAS
Under the European risk-based framework, this category covers lower-risk UAS operations that can be conducted without prior operational authorization when all applicable limitations are met.
Open Category
This umbrella term refers to an aircraft and the elements required to operate it when no person is aboard the aircraft.
Unmanned/Uncrewed Aircraft System (UAS)
This communications connection carries command, control, telemetry, and/or payload information between a control station and an aircraft.
Data Link
This United States civil aviation authority regulates U.S. airspace and establishes many requirements for civil drone operations.
Federal Aviation Administration (FAA)
This informal size classification is typically used for extremely lightweight UAS designed for highly portable or constrained-use applications.
Micros UAS
Under the European risk-based framework, this category applies to operations that present greater risk than open-category operations and generally require an authorization, declaration, or approved standard scenario.
Specific Category
This is the aircraft component of an RPAS that is flown by a remote pilot rather than carrying a pilot on board.
Remotely Piloted Aircraft (RPA)
This term emphasizes how human capabilities, limitations, workload, decision-making, and training influence system safety and performance.
Human Element
This European Union aviation safety organization develops common aviation rules and supports their implementation across participating European states.
European Aviation Safety Agency (EASA)
This classification generally describes lightweight UAS that are larger or more capable than micro systems but remain below broader small- or medium-system thresholds used by a given organization.
Very Small UAS
Under the European risk-based framework, this category applies to the highest-risk operations, for which aircraft certification, operator approval, and remote-pilot licensing may be required.
Certified Category