- Civil Aviation Authority (CAA)
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The Civil Aviation Authority is the UK's independent aviation regulator overseeing safety, airspace and economic regulation of civil aviation. Its remit includes drones and other UAS.
- Operator ID
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Unique number issued by the CAA to the person or organisation legally responsible for a drone or model aircraft. It must be affixed to any aircraft with a camera from 100 g upwards and to all drones at 250 g or more. Renew every 12 months.
- Beyond Visual Line of Sight (BVLOS)
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Flights conducted without direct visual contact between the pilot and aircraft. Allowed only under a Specific Category UK SORA authorisation with mitigations such as detect-and-avoid.
- Extended Visual Line of Sight (EVLOS)
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Former term for flights where a trained observer kept the aircraft in view while the pilot flew beyond direct sight. Now treated as BVLOS with visual mitigation under UK SORA rules.
- Beyond Visual Line of Sight with Visual Mitigation (BVLOS VM)
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BVLOS operation that uses trained observers along the route to monitor surrounding airspace. Requires specific authorisation with defined observer roles, communication and emergency procedures.
- Visual Line of Sight (VLOS)
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Flying with continuous unaided visual contact between pilot and aircraft to control the flight path and avoid collisions. This is the standard condition for Open Category flights.
- Notice to Airmen / Notice to Air Missions (NOTAM)
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Short-term advisory issued by aviation authorities about temporary changes or hazards affecting flight safety. Always check relevant NOTAMs before flying, especially in the Specific or Certified Categories.
- Drone Assist / Altitude Angel Drone Safety Map
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Free interactive map from Altitude Angel, endorsed by the CAA, showing live NOTAMs, airspace restrictions and ground hazards. Helps operators plan safe flights and notify authorities in some areas.
- General Visual Line of Sight Certificate (GVC)
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Main CAA qualification for Specific Category drone operations. Covers practical and theoretical aspects of safe VLOS flying.
- Assemblies of People
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Large gatherings where people cannot move away quickly in the event of an incident, such as concerts or sporting events. Drone flights over or near assemblies are heavily restricted or prohibited.
- Remote Pilot Certificate
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Qualification required for some advanced Specific or Certified Category operations involving higher risk or complex airspace. It demonstrates competence beyond basic Open Category requirements.
- Drone and Model Aircraft Code
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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 follow the Code.
- Specific Operations Risk Assessment (UK SORA)
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The CAA's step-by-step risk assessment method for Specific Category flights not covered by PDRA-01. It evaluates ground and air risks to set required safety objectives and mitigations, replacing the Operating Safety Case approach in April 2025.
- Pre-Defined Risk Assessment 01 (PDRA-01)
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Standard risk assessment published by the CAA allowing approved VLOS operations in built-up areas under the Specific Category. Operators comply with fixed limits and mitigations to fly without submitting a full SORA.
- Flyer ID
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Identification number issued by the CAA to a remote pilot who passes the online theory test; required before flying any drone or model aircraft that weighs 100 g or more. Valid for five years and strongly recommended for lighter aircraft.
- Operational Authorisation (OA)
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Written permission from the CAA allowing drone flights in the Specific Category, such as PDRA-01 or UK SORA operations. It sets the limits and safety requirements beyond the Open Category rules.
- Unmanned Aircraft System (UAS)
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An unmanned aircraft together with the control station and data-link equipment needed for safe operation; commonly called a drone.
- General Data Protection Regulation (GDPR)
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The UK's version of the EU GDPR governing the processing of personal data. Drone operators must comply when capturing personal data.
- Information Commissioner's Office (ICO)
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The UK's independent authority that promotes openness by public bodies and safeguards individual data privacy rights.
- Aeronautical Information Publication (AIP)
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Official publication containing aeronautical information essential to air navigation, including UK airspace data.
- National Air Traffic Services (NATS)
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The UK's main air traffic control service provider managing civil airspace.
- Civil Aviation Publication 722 (CAP 722)
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CAA guidance series providing policy and best practice for unmanned aircraft system operations.
- Flight Restriction Zone (FRZ)
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Legally defined zone around a protected aerodrome comprising its ATZ and runway protection areas; drones may enter only with explicit aerodrome or ATC permission.
- Aerodrome Traffic Zone (ATZ)
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Cylinder of airspace, typically 2 NM radius up to 2 000 ft AAL, established to protect traffic at an aerodrome and forming part of many FRZs.
- Runway Protection Zone (RPZ)
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Rectangular airspace about 5 km long and 1 km wide extending from each runway threshold up to 2 000 ft AAL; combined with the ATZ to create the FRZ.
- Radio Mandatory Zone (RMZ)
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Airspace in which two-way radio contact with the relevant ATS unit is mandatory before entry and throughout the flight.
- Small Unmanned Aircraft — General (ANO Article 94)
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Core rules for small unmanned aircraft under 20 kg requiring safe flight, visual contact and respect for people and property. Many obligations now appear in the Drone and Model Aircraft Code.
- Small Unmanned Aircraft — Prohibitions (ANO Article 94A)
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Prohibits flying a small unmanned aircraft in certain circumstances, such as inside an FRZ without permission or contrary to airspace restrictions. Breach of Article 94A is a criminal offence.
- Small Unmanned Aircraft — Commercial Operations (ANO Article 94B)
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Former provision regulating commercial drone operations, now largely replaced by UK UAS regulations and Operational Authorisations. Retained in amended form for certain legacy scenarios and enforcement.
- Small Unmanned Surveillance Aircraft (ANO Article 95)
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Adds extra restrictions to drones fitted with cameras or sensors, including separation from congested areas and people. Certain allowances exist in the Open Category.
- Endangering Safety of an Aircraft (ANO Article 240)
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Makes it illegal to recklessly or negligently cause or permit an aircraft, including a drone, to endanger another aircraft. Applies regardless of the unmanned aircraft's weight and carries severe penalties.
- Endangering Safety of Any Person or Property (ANO Article 241)
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Makes it an offence to recklessly or negligently endanger any person or property with an aircraft. This provision can be enforced even when other drone rules are not breached.
- UAS Operations in the Framework of Model Aircraft Clubs and Associations (Article 16 of UK Reg (EU) 2019/947)
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Allows the CAA to authorise recognised clubs and associations to fly under their own conditions. Members must follow the specific limits, sites and procedures set out in their association's Article 16 authorisation.
- Power to Issue Directions (ANO Article 265)
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Gives the CAA or authorised persons the ability to issue immediate directions restricting or prohibiting flight for safety or security reasons. These may be published as NOTAMs or formal notices.
- UK Reg (EU) 785/2004
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Retained UK regulation originating from EU 785/2004 that sets minimum insurance requirements for commercial air carriers and operators, including drones.
- Transponder Mandatory Zone (TMZ)
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Airspace where all aircraft must carry and operate an SSR Mode S transponder unless exempted.
- Open Category
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One of three UAS operation categories in UK Regulation (EU) 2019/947, covering low-risk flights in subcategories A1, A2 and A3. No CAA Operational Authorisation is required if all limits—such as weight under 25 kg, height ≤ 120 m and separation from people—are met.
- First Person View (FPV)
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Flying a drone using a live video feed from an onboard camera viewed through goggles or a screen. In the Open Category this is only allowed when a competent observer maintains unaided visual line of sight and can warn the pilot of hazards.
- Flight Level 660 (FL660)
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Altitude of 66,000 ft referenced to the standard pressure setting of 1013.25 hPa. Represents the upper limit of UK-controlled airspace used in the UK SORA policy framework.
- Air Accidents Investigation Branch (AAIB)
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UK government body that investigates civil aircraft accidents and serious incidents, including those involving drones. Serious occurrences must be reported to the AAIB without delay.