Aircraft: A device that is used or capable of controlled flight.

Airprox A+B: The two most severe forms of near-midair encounters, in which a collision is avoided either because of luck or evasive action.

Air traffic controller: A person who provides ground and/or airborne separation and traffic advisory services between aircraft.

Air Traffic Control Service: The category of ATS comprising area control service, approach control service and aerodrome control service.

Air Traffic Services (ATS): A generic term meaning variously, flight information service, alerting service, air traffic advisory service, air traffic control service (area control service, approach control service or aerodrome control service).

Air navigation service provider (ANSP): The organization delegated by the CAA (regulator) to provide air traffic services within its airspace. The ANSP may be privately owned, or part-owned by the government.

Air traffic management, ATM: The existing system for managing or controlling manned aircraft; includes Air Traffic Control (ATC) services.

Autopilot: An automated system that directly operates an aircraft.

Basic flight: A category of flights (or segment of a flight) that operates independently of traffic management services, taking full responsibility for safety and routing.

Beyond Visual Line of Sight, BVLOS: Operation of a drone beyond the visual line of sight of a remote pilot or observer. Compare VLOS (Visual Line of Sight).

Civil aviation authority (CAA): The regulatory agency responsible for the overall safety of the Member State’s airspace. It fulfills this role through a variety of activities, from pilot and aircraft certification to enforcement actions against operators who violate regulations. The regulator also influences and enacts aviation policy.

Corridor control service: A digital traffic management service that has authority for a specific corridor to safely manage the flow in, out, or through the corridor.

Detect and avoid: A system which allows aircraft to spot obstacles or dangers and take action to avoid collision without human intervention. This can happen through sensors on other aircraft or on the ground, which sends an alert to the endangered aircraft. Or it may occur when the autonomous vehicle itself senses a problem and acts on its own.

Distributed authority: A system in which any individual actor is able to make decisions and act based on information and a set of agreed rules, rather than refer to a central authority for permission.

Drone: An aircraft without a human pilot on board; includes unmanned aerial vehicle (UAV) and remotely piloted aircraft (RPA).

Digital traffic management services, or traffic manager: A service for assisting, organizing, and governing aircraft using digital means in the airspace. The service is responsible for preventing collisions and maintaining orderly flow. Compare with the ICAO term Air Traffic Services.

eVTOL: Electric or hybrid-electric vertical takeoff and landing aircraft; they can be winged or wingless, manned or unmanned, and have any number of applications from packages and cargo to air taxi.

Fleet supervisor: A person or automated system that manages flight plans, aircraft assignments, and performs business optimizations. The fleet supervisor dispatches aircraft with a flight plan that is followed by a pilot, autopilot, or supervisor.

Flight plan: A record of the intended route in time and space that an aircraft expects to follow while in flight. Flight Plan Request:A message sent from an operator to a flight planning service (which may be the same as the USS) that contains information about the vehicle and the mission of interest.

Geofence, geofencing: The creation of virtual boundaries in the airspace which constrain a drone, either to stay within its limits, or remain outside them. GPS spoofing:An attempt to fool a GPS receiver by broadcasting incorrect GPS signals.

Instrument flight rules, IFR: The regulations governing flight in which air traffic controllers are responsible for safely separating the aircraft from other aircraft, obstacles and terrain. Pilots are expected to adhere to all ATC clearances except in emergencies.

Local authority: A government or equivalent organization that has authority to set policy and restrictions on land and airspace usage within a local area.

Loss of separation: A safety event in which the horizontal and/or vertical distance between two aircraft is less than the required separation minima. Do not use the acronym “LOS,” which is commonly understood to mean “line of sight.”

Managed aircraft: An aircraft flying a managed flight under the guidance of a digital traffic management service.

Managed flight: A category of flights (or segment of a flight) where the path is controlled by a traffic management service which also provides separation services.

Managed flight rules, MFR: Airbus UTM’s proposed amendment to ICAO Annex 2 for vehicles that use UTM services for airspace access, where neither IFR nor VFR is appropriate.

NASA UTM: NASA’s UAS Traffic Management program started in 2015 in collaboration with the FAA and other federal agencies.

Operator: The person or organization that sets a mission for a drone, provides oversight of the drone in flight, and takes responsibility for the effects of the drone’s flight.

Overshadowing: An attack on computer systems in which a false signal is boosted to such levels it drowns out the accurate data.

Owner: The person or organization that owns the aircraft and is responsible for maintaining its airworthiness.

Pilot: A human operator of an aircraft (onboard or from the ground).

Regulator, regulatory agency: The singular organization that has legal authority to regulate air traffic in a location, along with that organization’s delegates (such as an ANSP).

Remote ID: The unique identifier for a UAS operation that can be accessed both digitally and at a distance.

Remotely piloted aircraft system, RPAS: Large UAS that is intended to operate under IFR in Class A airspace and interact with existing ATM systems. Often used in military and surveillance applications, with endurance of many hours and range of hundreds or thousands of kilometers.

Safety culture: The aviation industry focuses intensely on safety as a priority, including a conservative approach to operations, from task checklists to open communications.

Self-piloted aircraft: An aircraft whose flight path is managed exclusively by an autopilot without the need for a pilot.

Separation: The minimum safe distance required between aircraft, set by standards or regulation.

Service: The abstract provision of a function related to drone flight, provided to one or more stakeholders. For self-piloted or managed services, much but not all of the function is provided digitally.

Service provider: An organization that offers a collection of services that manage aircraft in flight, including drones and self-piloted aircraft. Compare to the ICAO term Air Traffic Services24.

SESAR Joint Undertaking: The technological pillar of Europe’s Single European Sky initiative, coordinating and concentrating all EU research and development activities.

Supervisor: A person (onboard or on the ground) who relies on an autopilot to operate an aircraft in normal conditions. The supervisor is available to intercede and provide a new plan to the autopilot or directly/remotely operate the aircraft. There may be a many-to-one relationship where one supervisor oversees multiple aircraft.

System Wide Information Management, SWIM: The FAA’s System Wide Information Management Program to implement a set of Information Technology principles and provide users with relevant and commonly understandable information.

System manager: A single, authoritative service to coordinate digital traffic services. This is implemented and operated under the auspices of government regulatory agencies. Scope will vary between countries.

Unmanned aerial system, UAS: A system that comprises the flying vehicle, communications link and any ground infrastructure, such as a handheld remote-control unit or a computer that sends commands to the vehicle.

Unmanned aerial vehicle, UAV: Unmanned aerial vehicle. An aircraft without a pilot on board controlling the flight.

UAV traffic services: Any service provided for assisting, organizing, and governing UAVs in the airspace. Compare the the ICAO term Air traffic services.

Unmanned Traffic Management, UTM: A networked collection of services that work together to safely direct self-piloted air traffic based on common rules.

Urban air mobility (UAM): The concept of using large UAS or helicopters to carry one or more passengers across or within a metropolitan area.

Vertiport: A facility used for loading, unloading, storing and servicing UAM vehicles. May be located on or adjacent to an airport.

Visual flight rules, VFR: The regulations governing flight in which the human onboard pilot is responsible for navigating and seeing and avoiding other traffic in conditions that meet or exceed prescribed weather minima. Use of air traffic control services is optional and generally advisory in nature, unless required for airspace access.

Visual Line of Sight, VLOS: Operation of a drone within visual line of sight of a remote pilot or observer. The remote pilot must be able to see the drone sufficiently well to have continuous awareness of its location, heading, and status, as well as the drone’s environment in order to avoid other aircraft, structures, and terrain.