The Open Category — the basics

Most hobby and light commercial drone flying in the UK happens in the Open category. It covers low-risk flights and needs no CAA operational authorisation, but it is split into three subcategories (A1, A2, A3) based on how close you can legally get to people.

All Open category flights share the same outer limits: maximum 120 metres above the ground (or above the highest point of a structure if flying within 50m of it, up to an extra 15m), and you must always keep the drone in your direct unaided visual line of sight (VLOS). No dropping articles or carrying dangerous goods.

A1, A2, A3 — who can fly where

• A1 (fly over people): sub-250g drones (C0) or C1-class drones. You can fly close to, but should avoid flying directly over, uninvolved people. Never fly over crowds.
• A2 (fly close to people): needs the A2 CofC. C2-class drones only, minimum 30m horizontal distance from uninvolved people, or 5m in low-speed mode. Cannot be flown over uninvolved people.
• A3 (fly far from people): C2, C3 or C4 drones (or legacy/privately-built), must stay at least 150m from residential, commercial, industrial or recreational areas, and well away from any uninvolved person.

The A2 Certificate of Competency

The A2 CofC lets you fly in the A2 subcategory. To get it you must already hold the A2 CofC theory knowledge (built on the A1/A3 online test) and pass a multiple-choice exam covering technical/operational mitigations, meteorology, and UAS flight performance, then complete a self-declared practical training log.

Key numbers to lock in

• 120m max height AGL across the whole Open category.
• 30m minimum distance from uninvolved people in A2 (or 5m in the drone's low-speed mode, where fitted).
• 150m from residential/recreational/commercial/industrial areas in A3.
• Under-250g (C0) drones get the most freedom — treated leniently in A1 and exempt from most registration/labelling rules.
• Operator ID must be registered with the CAA and displayed on any drone over 250g (or any drone with a camera, other than a toy).
• Flyer ID (proof of theory test pass) required to fly drones 250g and over, or any drone with a camera unless it is a toy.

Common mistakes

• Confusing 'avoid flying over people' (A1) with 'never fly over people' (A2/A3 — much stricter, uninvolved people must never be overflown in A2 or A3).
• Forgetting the low-speed mode 5m reduction only applies if the drone class genuinely supports it.
• Assuming sub-250g drones need no ID at all — a Flyer ID is still needed if it carries a camera.
• Mixing up drone class markings (C0-C4) with subcategory letters (A1-A3) — they are linked but not the same thing.
• Forgetting airspace restrictions (Flight Restriction Zones around airports, etc.) apply on top of Open category rules, not instead of them.

Why this matters

The A1/A2/A3 subcategories set out exactly where you can fly your drone relative to people, based on the class mark (C0-C4) or the transitional weight of the aircraft. Get these mixed up and you will fail questions on the exam and break the law in real life.

A1 - Fly over people (but not crowds)

• Covers C0 drones (under 250g) and C1 drones (under 900g, or under 800g for legacy/transitional).
• You may fly close to people and may overfly individuals, but you must never intentionally fly over an assembly of people (a crowd where people cannot move away easily).
• No minimum horizontal distance from uninvolved people is set in law for A1, but you should avoid flying directly over anyone for longer than necessary.
• C0 aircraft have the fewest restrictions since they are treated like low-risk toys.

A2 - Fly close to people

• Uses C2 class drones (under 4kg).
• Minimum horizontal distance from uninvolved people is 30 metres in normal flight.
• This can be reduced to 5 metres in low-speed mode (below 3 m/s), but only if the drone has that mode and you as the pilot have assessed the risk.
• You must never fly over uninvolved people in the A2 subcategory.
• Requires the A2 Certificate of Competency (A2 CofC) - this is on top of the basic A2 CofC theory certificate, plus practical self-declared training.

A3 - Fly far from people

• Covers C3 and C4 drones (900g to 25kg), or any drone not in a class mark (legacy aircraft).
• Must be flown at least 150 metres horizontally from residential, commercial, industrial and recreational areas.
• Must be flown so that it is not flown over or within 150 metres of people not involved in the flight.
• This is the most restrictive subcategory in terms of location, because the aircraft carries higher risk mass and no built-in mitigations.

Common mistakes

• Confusing A1 (over people, not crowds) with A2 (close but not over) - remember A1 is about height above individuals, A2 is about lateral distance.
• Forgetting the 5 metre low-speed exception only applies in A2, and only in low-speed mode.
• Thinking class marks are optional - if a drone has no class mark, it defaults to the most restrictive subcategory it can legally fly in (usually A3), based on weight bands under the transitional arrangements.
• Mixing up the 30m/5m figures for A2 with the 150m figure for A3 - these numbers come up constantly in exam questions.
• Assuming the Open Category rules override the need for permissions in controlled or restricted airspace - they do not; airspace rules always apply on top.

Why weather matters for the A2 CofC

Understanding meteorology is core to the A2 CofC because you must self-brief before every flight - there is no ATC to warn you. The exam tests both raw knowledge (fronts, clouds, pressure) and applied judgement (should I fly today?).

Wind

Wind is the single biggest factor for small drones because of their low mass and large surface-area-to-weight ratio.

• Wind speed generally increases with altitude, and surface friction slows wind near the ground - so wind at 50-120m can be noticeably stronger than what you feel standing on the ground.
• Gusting adds roughly a third on top of the mean speed as a rule of thumb - a 15kt mean wind can gust to 20kt+.
• Always check the manufacturer's maximum demonstrated wind speed for your aircraft and treat it as a limit, not a target.
• Wind direction affects launch/recovery choices and battery consumption - flying into wind on the way out uses more power, so plan the return leg with reduced battery in mind.

Pressure, fronts and stability

• Low pressure systems bring rising air, cloud, rain and stronger winds; high pressure systems bring sinking air, clearer skies and calmer conditions - but can also trap fog or mist near the ground (temperature inversion).
• A cold front passing brings a sharp wind shift, a brief spell of heavier rain, and a temperature drop; a warm front brings a longer period of thickening cloud and steady rain ahead of it.
• Convective (unstable) conditions on warm days build cumulus cloud and can produce gusty, unpredictable local winds even when the forecast mean wind looks fine.

Visibility and cloud

• You must maintain Visual Line of Sight (VLOS) at all times under the Open Category - poor visibility, haze, mist or low cloud can break this legal requirement even if the drone is still in range.
• Cloud base matters if you are flying near any airspace with a ceiling, since low cloud can force other aircraft down to your operating height.
• Rain, fog and precipitation reduce your ability to see the aircraft and can also damage electronics not rated for wet weather.

Temperature and other effects

• Cold temperatures reduce battery performance and flight time significantly - always allow a larger margin and warm batteries before flight in winter.
• Hot, humid conditions reduce air density, which reduces propeller lift efficiency, especially at altitude.
• Static electricity and lightning risk rise during thundery conditions - never fly near or under cumulonimbus cloud.

Common mistakes

• Only checking ground-level wind and ignoring that it is stronger higher up.
• Ignoring gust factor and flying right up to the steady-wind limit.
• Forgetting that a clear-looking high-pressure morning can still hide fog or an inversion layer.
• Not rechecking weather immediately before takeoff, since conditions can change fast between planning and flying.

Always get a proper pre-flight briefing (METAR/TAF or a dedicated aviation weather app) rather than relying on a general phone weather app, which does not give aviation-specific detail like cloud base or wind at height.

Why flight performance matters

Every drone flight is a balancing act between lift, drag, weight and thrust. As a remote pilot you need to understand how conditions and battery state change that balance, because performance loss is one of the biggest causes of loss of control in the Open Category.

Wind and weather effects

• Wind speed generally increases with altitude and is stronger over open ground, hills and near buildings (turbulence and gusting).
• Small multirotors are especially vulnerable to wind because of their low mass - always check the manufacturer's maximum demonstrated wind speed before flying.
• Cold temperatures reduce battery performance and chemical efficiency; hot temperatures can cause overheating and reduced motor efficiency.
• Rain and moisture can damage electronics and reduce control authority - most Open Category drones are not waterproof.
• Always check a proper aviation weather source (e.g. Met Office, NOTAMs) before flying, not just a general weather app.

Battery care - the core rules

• Almost all consumer drones use Lithium Polymer (LiPo) or Lithium-ion batteries - both are energy-dense but can catch fire if damaged, overcharged or short-circuited.
• Never charge a battery unattended, and always charge on a fireproof surface or in a proper LiPo charging bag.
• Store batteries at around 40-60% charge (storage voltage) if not flying for a while - storing fully charged shortens lifespan and increases fire risk.
• Never fly a battery that is swollen, punctured, dented or shows signs of damage - these are fire hazards and must be disposed of correctly (not in household waste).
• Keep batteries within their recommended temperature range for charging and flying - cold batteries deliver less power and can be permanently damaged if charged when too cold.
• Always land with a safe reserve of charge - a common rule of thumb is to land with at least 20-30% remaining, since power delivery drops sharply as a LiPo nears empty.
• Battery voltage sag under load (e.g. in wind or during climbs) can trigger a low-voltage warning or failsafe even if the percentage displayed seems adequate.

Performance factors to weigh up

• Payload weight reduces available flight time and manoeuvrability, and increases stall/crash risk if the drone is overloaded beyond its rated maximum take-off mass.
• Altitude reduces air density, which reduces lift and can reduce battery and motor efficiency, especially at higher sites.
• Always plan flight time conservatively, factoring in wind, cold, payload and a safe landing reserve, not just the manufacturer's quoted maximum flight time.

Common mistakes

• Assuming displayed battery percentage is linear and reliable right down to zero.
• Flying in gusts beyond the drone's rated wind tolerance because the sky 'looks calm' at ground level.
• Charging or storing batteries indoors on flammable surfaces without supervision.
• Ignoring temperature effects on both battery performance and airframe/lift performance.

Why risk assessment matters

Under the A2 CofC, you fly in the Open Category subcategory A2, close to people but never over uncontrolled crowds. You are not required to submit an operational risk assessment like a PDRA or SORA operator would, but the exam still tests that you understand risk THINKING - because it is the mindset the A2 subcategory is built on.

The A2 'low and slow' principle

• A2 lets you fly closer to uninvolved people than A1, but only because you accept extra self-imposed limits.
• Best-practice guidance (the CAA-endorsed A2 code of conduct) says to slow down near people and fly at reduced speed in built-up or populated areas.
• Horizontal distance from uninvolved people: 30m normal, or 5m in the low-speed 'slow mode' when using a C2-class aircraft (or a transitional sub-250g/legacy aircraft) with genuine speed-limiting engaged.
• You must never fly directly over uninvolved people, regardless of distance rules.

Ground risk vs air risk

• Ground risk = harm to people/property below (crowd size, urban density, fragile structures, roads, traffic).
• Air risk = collision with other aircraft (manned aviation, other drones), highest near aerodromes and in controlled airspace.
• Mitigate ground risk by choosing sparser sites, flying higher above obstacles where legal, and picking flight paths away from crowds and roads.
• Mitigate air risk by checking NOTAMs, using a drone-safety app (e.g. Drone Assist), and staying below 120m (400ft) AGL unless a specific exception applies.

Practical mitigations to know

• Site survey before flying: check for people, animals, powerlines, roads, fragile/sensitive sites.
• Weather check: wind speed limits for your airframe, rain, and visibility (you must maintain VLOS).
• Battery and equipment checks pre-flight - technical failure is a common cause of loss of control.
• Have a contingency plan: what you'll do if you lose signal, GPS, or battery runs low (return-to-home, controlled landing away from people).
• Keep a safe operating distance from your own take-off/landing point and any bystanders who are not under your control.

Common mistakes

• Confusing the A2 subcategory distances (30m/5m) with the A1 'avoid overflight' rule - A1 has no fixed distance, A2 does.
• Forgetting that 5m slow mode ONLY applies with genuine low-speed setting and appropriate aircraft class.
• Assuming risk assessment is only 'paperwork' - the exam tests your understanding of WHY each mitigation exists, not just the numbers.
• Overlooking air risk (airspace/NOTAMs) and focusing purely on people on the ground.

Why this topic matters

The A2 CofC tests more than flying skill - you need to know your legal duties around privacy, insurance and registration before you ever take off. Get these wrong and you are breaking the law even if the flight itself is safe.

Privacy

• The UK GDPR and Data Protection Act 2018 apply if your drone captures identifiable people, number plates or private property - this counts as processing personal data.
• You do not need to register with the ICO for purely personal, non-commercial flying (the 'household exemption'), but commercial operators generally do need to register and pay the ICO fee.
• Avoid hovering over or recording private gardens, windows or people without consent - this can also breach the Protection from Harassment Act and local privacy law even outside GDPR.
• Good practice: only capture what you need, tell people nearby what you are doing, blur or delete footage you do not need, and have a clear reason (purpose) for each recording.
• Common mistake: assuming 'flying is legal so filming is automatically fine' - the flight rules (CAA) and the data rules (ICO) are separate and both apply at once.

Insurance

• If you fly for any commercial purpose (paid work, including social media promotion for a business), you are legally required to hold third-party liability insurance under EC Regulation 785/2004 as retained in UK law.
• This applies regardless of drone weight - there is no small-drone exemption for commercial insurance.
• Purely recreational flying does not carry a legal insurance requirement, but the CAA and BMFA strongly recommend it anyway, since you are liable for any damage or injury you cause.
• Common mistake: thinking a sub-250g drone is exempt from insurance rules because it is exempt from some registration rules - weight has no bearing on the insurance requirement.

Registration (Operator ID and Flyer ID)

• Anyone who owns or is responsible for a drone or model aircraft between 250g and 25kg (or any drone with a camera, unless it's a toy under the Toy Safety Directive) must register for an Operator ID with the CAA.
• The Operator ID must be displayed on every drone the operator is responsible for, and it is valid for 12 months, renewable annually for a fee.
• Anyone flying a drone in the Specific or Open category that needs to pass a theory test (like the A2 CofC) must hold a Flyer ID, gained by passing the relevant CAA online test - this is personal to the pilot, not the drone.
• A single person can hold both IDs; a 12-13 year old can get a Flyer ID but must be 18+ for an Operator ID.
• Common mistake: confusing the two - Operator ID = who is responsible for the aircraft (can be an organisation); Flyer ID = the individual who has proven they know the rules by passing a test.
• Registration numbers must be clearly and durably marked on the drone airframe, not just written on a label that could fall off.

Quick tie-together

Before any commercial or camera-equipped flight: check you (1) respect people's privacy and data rights, (2) hold valid insurance if it's commercial, and (3) have a current Operator ID displayed on the aircraft and a Flyer ID for the pilot if required.