- CAA (Civil Aviation Authority)
-
The UK's independent aviation regulator, overseeing safety, airspace and economic regulation of civil
aviation, including drones and other UAS.
- Operator ID
-
A unique number issued by the CAA to the person or organisation that is legally responsible for a drone or
model aircraft; it must be affixed to any aircraft over 250 g or with a camera and is renewable every 12
months.
- BVLOS (Beyond Visual Line of
Sight)
-
Operations where the pilot no longer has direct visual contact with the aircraft; permitted only under a
Specific Category UK SORA Operational Authorisation with suitable mitigations such as detect-and-avoid.
- EVLOS (Extended Visual Line of Sight)
-
Operations where the aircraft is flown beyond the direct line of sight of the remote pilot, but remains within visual range of a trained observer who maintains unaided visual contact. The observer assists the pilot in situational awareness and collision avoidance. EVLOS is permitted under a Specific Category Operational Authorisation and requires effective communication between the pilot and observer at all times.
EVLOS is no longer considered a type of operation by the CAA; any operation previously classified as EVLOS is now considered a form of BVLOS (Beyond Visual Line of Sight) known as BVLOS VM (Beyond Visual Line of Sight with Visual Mitigation) and must meet all applicable BVLOS requirements under the UK SORA framework.
- BVLOS VM (Beyond Visual Line of Sight with Visual Mitigation)
-
A subset of Beyond Visual Line of Sight operations where the risk of airborne collisions is mitigated by deploying trained visual observers (Visual Mitigation personnel) along the flight path. These observers are positioned to maintain unaided visual contact with the airspace around the drone, not necessarily the drone itself. BVLOS-VM operations are typically authorised under the Specific Category with a UK SORA Operational Authorisation and must include clearly defined observer roles, communications protocols, and emergency procedures.
- VLOS (Visual Line of Sight)
-
A type of UAS operation in which, the remote pilot is able to maintain continuous unaided visual contact
with the unmanned aircraft, allowing the remote pilot to control the flight path of the unmanned aircraft
in
relation to other aircraft, people and obstacles for the purpose of avoiding collisions.
- NOTAM (Notice to Airmen / Notice to Air Missions)
-
A short-term advisory issued by aviation authorities to alert pilots and airspace users to temporary changes or hazards affecting flight safety. This may include information on airspace restrictions, drone flight prohibitions, military exercises, airshows, or emergency response zones. NOTAMs are published via the Aeronautical Information Service (AIS) and should always be checked before any drone operation, especially in the Specific or Certified Categories.
- Drone Assist / Altitude Angel Drone Safety Map
-
A free interactive map and situational awareness tool developed by Altitude Angel and endorsed by the UK Civil Aviation Authority. It displays live NOTAMs, airspace restrictions, FRZs, ground hazards, and other safety information relevant to drone flights. Available as a mobile app and web platform, Drone Assist helps operators plan safe and legal flights by identifying no-fly zones and notifying relevant authorities of planned operations in some areas.
- GVC (General Visual Line of Sight Certificate)
-
The primary CAA qualification for Specific Category drone operations, required for most commercial flights under an Operational Authorisation. The GVC covers practical and theoretical aspects of safe VLOS flying.
- Assemblies of People
-
Large gatherings where people cannot move away quickly in the event of an incident, such as concerts, festivals, sporting events, demonstrations, or crowded streets. Drone flights over or close to assemblies are heavily restricted or prohibited.
- Remote Pilot Certificate
-
A formal qualification required for some advanced Specific Category or Certified Category drone operations, typically involving more complex risk or airspace scenarios.
- Drone and Model Aircraft Code
-
The official UK rules and guidance for flying drones and model aircraft safely and legally in the Open Category, covering privacy, safety, and airspace awareness. Every pilot should know and follow the Code.
- UK SORA (Specific Operations
Risk
Assessment)
-
The CAA's step-by-step risk-assessment process for Specific Category drone flights that aren't covered
under
Pre-Defined Risk Assessment 01 (PDRA-01). It weighs ground and air hazards, assigns a 'SAIL' score and
sets
the
safety measures you must meet. UK SORA went live on 23 April 2025, replacing the former Operating Safety
Case (OSC) method.
- PDRA-01 (Pre-Defined Risk
Assessment 01)
-
A standardised risk assessment published by the UK CAA that allows approved VLOS drone operations within
built-up areas under the Specific Category.
- Flyer ID
-
Identification number issued by the CAA to a remote pilot that has passed the CAA's online theory test;
required before flying any drone ≥ 250 g. Valid for five years.
- OA (Operational Authorisation)
-
Written permission issued by the UK Civil Aviation Authority (CAA) allowing drone flights in the Specific
Category, such as PDRA-01 or UK SORA operations. The OA sets the limits and safety requirements for your
planned activities beyond the Open Category rules.
- UAS (Unmanned Aircraft System)
-
An unmanned aircraft together with the control station and data-link equipment needed for its safe
operation; commonly called a drone.
- GDPR (General Data Protection
Regulation)
-
The UK GDPR is the UK's version of the EU General Data Protection Regulation, governing processing of
personal data.
- ICO (Information Commissioner's
Office)
-
The UK's independent authority that promotes openness by public bodies and safeguards individual
data-privacy rights.
- AIP (Aeronautical Information
Publication)
-
Official publication containing aeronautical information essential to air navigation, including UK airspace
data.
- NATS (National Air Traffic
Services)
-
The UK's main air traffic control service provider, managing civil airspace in the UK.
- CAP 722
-
A UK CAA publication series (CAP) providing guidance on unmanned aircraft systems operations.
- FRZ (Flight Restriction Zone)
-
A legally defined zone around a protected aerodrome comprising its ATZ and runway protection areas; drones
may enter only with explicit aerodrome or ATC permission.
- ATZ (Aerodrome Traffic Zone)
-
A cylinder of airspace (typically 2 NM radius to 2 000 ft AAL) established to protect traffic at an
aerodrome; forms part of many FRZs.
- RPZ (Runway Protection Zone)
-
A rectangular airspace block extending about 5 km from each runway threshold (≈ 1 km wide to 2 000 ft AAL)
that safeguards arriving and departing aircraft; combined with the ATZ to create the FRZ.
- RMZ (Radio Mandatory Zone)
-
Airspace where two-way radio contact with the relevant ATS unit is compulsory before entry and throughout
the flight.
- ANO Article 94 (Small Unmanned Aircraft — General)
-
The core rule set applying to all small unmanned aircraft (drones) under 20 kg. It requires pilots to only fly if they are reasonably satisfied the flight can be made safely, to maintain direct visual contact unless authorised otherwise, to avoid endangering any person, property or other aircraft, and to comply with height and distance limits. Many of these requirements now appear in the Drone and Model Aircraft Code.
- ANO Article 94A (Small Unmanned Aircraft — Prohibitions)
-
Prohibits flight of a small unmanned aircraft in certain circumstances, such as within a Flight Restriction Zone (FRZ) without permission, or in a manner that contravenes applicable airspace restrictions, unless authorised. Breach of Article 94A is a criminal offence.
- ANO Article 94B (Small Unmanned Aircraft — Commercial Operations)
-
Formerly the main provision regulating “commercial operations” with small unmanned aircraft, now replaced by the UK UAS implementing regulation and CAA Operational Authorisation requirements. It is retained in amended form for certain legacy scenarios and enforcement.
- ANO Article 95 (Small Unmanned Surveillance Aircraft)
-
Applies extra restrictions to drones fitted with cameras or sensors capable of recording data. It prohibits flight over or within 150 m of congested areas and within 50 m of people, vehicles, vessels or structures not under the control of the operator, except where permitted by CAA authorisation. Certain allowances exist in the Open Category.
- ANO Article 240 (Endangering Safety of an Aircraft)
-
A general offence making it illegal to recklessly or negligently cause or permit an aircraft (including drones) to endanger another aircraft. This provision applies regardless of the weight of the unmanned aircraft and carries severe penalties, including potential imprisonment.
- ANO Article 241 (Endangering Safety of Any Person or Property)
-
A broad safety provision making it an offence to recklessly or negligently cause or permit an aircraft (including drones) to endanger any person or property. This applies in addition to more specific drone rules and can be enforced even where other articles are not breached.
- ANO Article 265 (Power to Issue Directions)
-
Gives the CAA and authorised persons the power to issue immediate directions restricting or prohibiting flight, including drone operations, for safety or security reasons. These may be issued as NOTAMs or formal notices.
- TMZ (Transponder Mandatory Zone)
-
Airspace of defined dimensions in which all aircraft must carry and operate an SSR (Mode S) transponder
unless exempted.