Home Blog articles Drones – Acronyms and Terms

Drones – Acronyms and Terms

by Fabio Affortunato
Drones Acronyms and terms
Reading time / Tempo lettura : 6 minutes / minuti

Drones, UAV, UAS, RPAS – Glossary of acronyms and terms

This article describes the acronyms and terms used in the field of drones, SAPR, APR and UAV and related technologies.

For each acronym-term an attempt has been made to provide as complete and exhaustive an explanation as possible

Acronyms are listed in alphabetical order.


AGL: Above Ground Level – English acronym to indicate elevation above ground level.

APR: Remote Piloted Aircraft – Alternative term used to indicate drones. For more information read article meaning SAPR, APR, UAV, UAS, sUAS.

ARF: Almost Ready to Fly – The term is used to identify those that need assembly or lack components / accessories such as the flight controller in order to fly.

ATZ: Aerodrome Traffic Zone Indicates an airport traffic zone, forbidden to fly with drones.


BLOS: Beyond Line Of Sight – Indicates the operating area of a drone, far enough away from the pilot, so he loses visual contact with the drone itself. The BLOS operations takes on a critical character.

BNF: Bind and Fly – Drones to be connected in order to fly. This name generally indicates drones without the flight controller, which must be purchased separately.

Brushless – Term used to identify an engine indicates brushless. Brushless motors have less mechanical resistance and zero risk of sparks.


Class – By class XYZ we mean the diameter of the drone. For a class 300 drone the diagonal will measure 300mm.

Critical Operation – Indicates that type of transaction that does not comply, even in part, with the limitations imposed on non-critical transactions. For more details see the ENAC regulation on critical operations.

CTR: Controlled Traffic Region – Controlled airspace.


D&A: Detect & Avoid – Pilot’s ability to avoid collisions with vehicles and aircraft, critical conditions also through the use of auxiliary systems.

DIY: Do It Yourself – The term is used to indicate those drones that need to be assembled before they can fly. The acronym is also used to identify a component of the drone that can be purchased individually.


EASA: European Aviation Saftey Agency – European Aviation Safety Agency.

ENAC – National Agency for Civil Aviation (Italy).

ESC: Electronic Speed Controller – Indicates the electronic component that can guarantee the correct operation of the drone’s motors.

EVLOS: Extended Visual Line Of Sight – Identifies the operations conducted in areas whose dimensions exceed the limits of the conditions of visual flight. The operations carried out in EVLOS always intend to maintain visual contact with the drone through the use of devices.


F.A.A.: Federal Aviation Administration – The Department of Transportation of the United States of America, which has the authority to regulate and supervise all aspects of American civil aviation including drones.

Firmware – Device control and management software.

Fixed wing – Term used to identify those drones with wings similar to those of planes and normally equipped with a single propeller that provides the thrust for the flight.

Flag/s – Term used to indicate flags, integral parts of racing circuits, which delimit some sections of the racing circuit.

Flight controller – It is the on-board control unit that represents the drone’s autopilot system. This processes the flight data and takes care of keeping the multicopter “in balance” during the flight. To function, it interfaces with the IMU unit.

FPV: First Person View – It refers to the piloting of a drone through the direct view given by the video camera through special viewers. FPV flight is used mainly / exclusively for piloting competition drones. It is an accessory allowed in drone races.

Frame – Indicates the structural part of the frame of a drone.


Gates – English term used to indicate a semicircular or arched door, an integral part of racing circuits, through which competition drones pass at speed.

Gimbal – Camera/video stabilization system. It is used to eliminate flicker, vibrations and jolts while shooting in flight with the drone.

GPS: Global Positioning System – Global positioning satellite system. Many types of drones use GPS for flight and positioning relative to the No Fly Zone.


Hop/s – Term used to indicate circular rings, integral parts of racing circuits, through which competition drones pass at speed.

Hovering – Identify flight at zero speed and constant altitude of a drone. It consists of being stationed in flight at a fixed altitude.


IMUInertial Measurement Unit – It is a set of electronic components that are fundamental for the operation of the drone. This part may include: GPS antennas, gyroscopes, accelerometers, barometers, inertial measurement instruments, etc., which allow the Flight Controller to improve the response to sudden changes in factors affecting flight.

Indoor – Space confined within closed spaces, sometimes used for indoor drone competitions. Indoor spaces must have specific characteristics for drone races.



KPIs: Key Performance Indicators – They indicate the key parameters used for the performance evaluation of a system. 4mydrone first in the world, has defined a set of KPIs for the performance of a drone.


Laps counter – Term used to indicate electronic devices, integral parts of racing circuits, capable of counting the number of laps made by the drone in a racing circuit.

Launch/Landing pad – Term used to indicate the bases of take-off / landing of drones. They can be part of the racing circuits. They are normally used to make the drone take off/land avoiding making it come into contact with grass or the ground.

LED – Lights used by drones. Red and green color indicate the rear or front (bow) of the drone.

LIDAR: Light Detection and Ranging – It is a laser pulse detection system, which allows you to determine the distance of an object or surface. LIDAR devices are implemented on professional drones for carrying out specific activities.

LI.PO.: Lithium Polymer – They are a particular type of rechargeable battery that is part of the RC world, in particular for multicopters (drones). LiPo batteries are the main reason why electric flight is a much more valid solution than flight with combustion.

LOS: Line of Sight – In drones, the LOS is the flight view of the drone, the direct vision.


MTOM – Max Take-Off Mass, indicates the maximum weight that an aircraft takes off. It is a synonym of MTOW.

MTOW – Max Take-Off Weight, or also MTOM, maximum take-off mass, indicates the maximum weight of an aircraft at take-off. In aeronautical terms, therefore, the weight not to be exceeded, so as to avoid potential structural damage and a decrease in the performance of the aircraft in the take-off phase.

Motors – Term indicating the engines of drones. These can also be brushless.


NFZNo-Fly Zone, or an indication of an area where drone flying is not allowed.

Non Critical Operation – Indicates that type of operation conducted in VLOS and which does not involve overflight, of gatherings of people, urban agglomerations and sensitive infrastructures. For more details see the ENAC regulation on non-critical operations.


OSD: On Screen Display – It is the visualization on the radio controller of the flight data sent by the drone (telemetry).


Payload – In the aeronautical field it is identified as the paying load, and indicates the total weight that the aircraft must lift from the ground, given by the sum of the weight of the aircraft itself (chassis, electrical components, etc.) and any loads present. In the field of drones, the term payload identifies the sensor, the camera or another device added to the drone to carry out a specific activity.

PNP: Plug-N-Play. That is a drone-UAV, equipped with everything necessary except for a transmitter, a receiver battery and a charger. Contains servos, motor and ESC.

Propellers: Devices that ensure the flight of the drone. They are mounted on engines.

Propeller protecion – It is the protection for the drone’s propeller. In the event of a drone collision with an object, the function performed by the para-propeller is to avoid damage to the propeller and consequently to the engine.

Power backup – Term indicated for auxiliary electricity supply systems.



RC: Radio Control or Radio Controller – It is the radio control device of drones, airplane models and more. The radio controller is therefore the device used to control the flight of the drone and which in some cases can be connected to a smaprtphone or tablet.

Rotor – The rotor is a component that rotates around its axis to generate and / or transmit power. Well known are the rotors of a helicopter. In a drone the rotor is the rotating core of the electric motor.

Rotors – The term identifies those drones equipped with four or more propellers which provide the necessary thrust to fly

RPAS: Remotely Piloted Aircraft System – Acronym for a remotely piloted system. For more information read article meaning SAPR, APR, UAV, UAS, sUAS.

RTF: Ready To Fly – The term is used to identify those ready-to-fly drones, which do not need additional components / accessories to be able to fly.


SAPR – An acronym for Remote Piloted Aircraft System, also used to indicate a drone. Indicates an airplane without people on board, controlled by a remote pilot. The acronym does not apply to unmanned aerial systems used for recreational purposes and / or competitions (racing drone). For more information read article meaning SAPR, APR, UAV, UAS, sUAS.

SAPR observer – person designated by the pilot to assist also through visual observation, during the piloting of the SAPR.

S&A: See and Avoid – Pilot’s ability to avoid collisions with vehicles and aircraft, critical conditions through direct vision.

Sensore – The sensor is a device capable of detecting variations of a certain size to store it and/or transmit it to the processing systems. Sensors are also present in commercial drones. Normally the term sensors indicate those payloads capable of performing a specific measurement function, such as detectors of gas, chemicals, IR, etc.

Spare/s – Term for one or more spare parts of a drone. May include batteries, chassis, propellers, ESC, etc.



UAS: Unmanned Aerial System – Acronym for remotely piloted aircraft system. For more information read article meaningSAPR, APR, UAV, UAS, sUAS.

UAV: Unmanned Aerial Vehicle – Acronym used to indicate a remotely piloted aircraft. For more information read article meaning SAPR, APR, UAV, UAS, sUAS.


VFR: Visual Flight Rules – Set of the necessary and sufficient rules for the visual flight of an aircraft/drone.

VLOS: Visual Line of Sight – Term indicated for those operations with drone carried out in conditions in which the pilot always remains in visual contact with the drone vehicle.

VMC: Visual Meteorological Condintions – Indicates the weather conditions for flying in VFR conditions.

VTOL: Vertical Take-Off and Landing – Indicates an aircraft capable of taking off and landing vertically.





For more information on the definitions and acronyms used by the EASA European regulation, read the article “Drones-UAVs – Definitions and acronyms for orientation” from the Blog.

Note relating to images: The use of images is exclusively for the purpose of a better understanding of the contents of the article. The highlighted image was created by 4mydrone.

Go Up

Last Updated on/Ultimo aggiornamento – 29/04/2020

Related Posts

Leave a Comment