2.2 VLOS, 120 m Height Limit & Flight Restriction Zones

Common Open Rules Still Apply After You Pass A2

Passing the A2 CofC theory exam and obtaining the certificate does not create a separate airspace system. Near People (A2) only changes how close you may operate to uninvolved people (and which class marks / masses you may use there). All other Open Category remote-pilot responsibilities still bind you. The items in this section appear constantly in CAA “where you can fly” material and in the remote-pilot responsibilities under UK Regulation (EU) 2019/947 (as retained and amended in UK law), with practical framing in CAP 722 and the Drone and Model Aircraft Code.

If an exam stem says “the pilot holds a valid A2 CofC” and then offers an option that violates VLOS, climbs above 120 m, enters an FRZ without permission, drops a package, or flies at night without a green light, that option is still wrong.

Visual Line of Sight (VLOS)

VLOS means continuous, direct, unaided visual contact sufficient to control the flight path in relation to other aircraft, people, and obstacles. “Unaided” permits ordinary corrective lenses but not binoculars, telescopes, or a camera feed as the only visual reference.

The normal arrangement is that the remote pilot sees the aircraft and scans the surrounding airspace. UK rules also allow assistance by an unmanned-aircraft observer. For FPV flight, the observer must be co-located with the remote pilot, maintain direct unaided visual contact with the aircraft, keep an effective surrounding-airspace scan, and communicate clearly so the pilot can act immediately. The observer is not an independent BVLOS relay and does not remove the remote pilot’s responsibility for the operation.

VLOS decision points

• A screen can provide telemetry and framing, but screen-only flight without the permitted observer arrangement is not Open VLOS.
• Hearing the aircraft is not visual contact.
• A chain of observers extending range is not an Open-category substitute for VLOS.
• Buildings, trees, fog, glare, darkness, and background clutter can shorten the practical VLOS range.
• If visual contact or the airspace picture cannot be maintained, reduce range, reposition or land.

An observer can call traffic and help an FPV pilot maintain the legal visual function, but the crew must agree clear calls and the remote pilot must be able to discontinue the flight promptly. No observer arrangement authorises BVLOS.

The 120 m (400 ft) Height Limit

Open Category flights normally remain no more than 120 metres (400 feet) from the closest point of the surface of the earth. In this rule, the reference is the terrain—level ground, a slope, cliff, hill, or valley side. It is not the surface of a building, tree, crane, or other artificial object.

This is not simply “120 m above take-off.” When terrain rises or falls, the pilot must keep the aircraft within 120 m of the nearest terrain surface while also respecting VLOS, airspace, and people rules. Controller height measured from the home point may not represent the legal terrain-relative distance.

Artificial-obstacle exception

A limited exception can apply when an artificial obstacle is taller than 105 m:

• the operation is requested by the entity responsible for the obstacle;
• the aircraft remains within 50 m horizontally of it; and
• it flies no more than 15 m above the obstacle’s height.

This is not a general permission to measure 120 m from any roof or tree. Without all exception conditions, use the normal closest-terrain rule.

Height compliance does not open an FRZ, cure a VLOS loss, or replace A2 separation. A flight can satisfy one layer and still fail another.

Restricted Airspace and Flight Restriction Zones (FRZs)

CAA Open Category “do not” lists are blunt: do not fly in restricted airspace. For most remote pilots the highest-profile example is the Flight Restriction Zone (FRZ) around protected aerodromes (airports and certain other sites). Inside an FRZ, standard Open flying is not freely available. You need the permission process published for that aerodrome / zone (often involving the aerodrome operator and, where required, ATC), and you must follow any conditions attached.

How to treat FRZs on the exam and in practice

1. Assume FRZs are closed until permission exists. “I stayed below 120 m” or “I held A2 CofC” never opens an FRZ by itself.
2. Use official sources. Check current CAA / NATS drone maps and aeronautical information. Do not rely on a third-party app screenshot of unknown date, a mate’s memory, or the fact that you saw another pilot there last year.
3. Other restrictions exist. Restricted areas, danger areas, prohibited areas, temporary restrictions (NOTAMs / airspace usage plans), and site-specific byelaws can all stop a flight even outside a named airport FRZ. Open Category compliance is airspace-aware, not only people-distance-aware.
4. Plan before you drive. Discovering an FRZ after unpacking gear is how commercial jobs turn into illegal flights under time pressure — and how exam scenarios test whether you abort.

Restricted airspace vs A2 “near people”

A2 is about people and ground risk. FRZs and restricted airspace are about protecting manned aviation and sensitive sites. You can satisfy every A2 horizontal distance and still be illegal if you are inside a closed FRZ. Keep the two control layers separate in your mind:

Night Flying: Green Flashing Light

If you fly a drone or model aircraft at night in the Open Category, the aircraft must have a green flashing light turned on. CAA material ties this to UAS.OPEN.060 remote-pilot responsibilities: when operating at night, ensure a green flashing light on the unmanned aircraft is activated.

Key compliance points:

• The light must remain active throughout the night flight. If it fails or is switched off (including modes that disable it for filming), you are no longer meeting the Open night requirement.
• The remote pilot is responsible for ensuring the light is on — not the manufacturer marketing page and not a client.
• Some class marks must provide built-in green flashing light capability; UK0, UK4, and many legacy aircraft may need a securely fitted aftermarket light. Any added light counts toward mass, which can change class / sub-category eligibility.
• Night does not remove VLOS, height, FRZ, or people-distance rules. Darkness makes VLOS and conflict detection harder; keep night Open flights simple and close enough to maintain the visual picture.

Dangerous Goods and Dropping Articles

Across Open Category sub-categories the CAA “do not” list includes:

• Do not carry dangerous goods
• Do not drop articles

Open Category is not a delivery-operations category. If a scenario involves releasing a package, dispersing a substance, or carrying dangerous goods, the correct response is that Open Category does not permit that activity — you would need an appropriate authorisation route outside basic Open privileges, not a creative A2 interpretation.

Privacy, Nuisance, and Landowner Permission

Two separate duties often appear together in CAA guidance:

Privacy and nuisance

You must respect people’s privacy and not cause a nuisance. Cameras on modern UAS make privacy a live issue even when the flight is technically inside A2 distances. On the exam, “I had A2 separation, so privacy does not apply” is false. Separation rules manage collision and injury risk; privacy and nuisance duties manage how you affect people and property even when they are not struck.

Take-off and landing permission

You must make sure the person or organisation that owns the land where you want to take off and land allows you to do so. Open Category airspace privileges (where airspace is unrestricted) are not a right to use private land as a launch pad. Common exam traps:

• Public highway or car park without checking who controls it
• School or hospital grounds without site permission
• Client’s neighbour’s garden used as the only clear launch point

Airspace may be legal while the surface site is not. Get permission for the take-off and landing site before you treat the job as ready.

Insurance Snapshot (Context, Not a Substitute for Legal Advice)

CAA Open guidance notes that if you fly for recreation or sport you can choose whether to hold insurance, but if you fly commercially you must have third-party insurance. Breaking ID and flying rules can lead to fines and, in serious cases, prosecution. For A2 CofC candidates, the exam-relevant idea is simple: commercial A2 work still sits inside Open common rules and still needs the insurance duty that applies to commercial UAS operations.

Pre-Flight Open Compliance Checklist

Use this as a mental scan before any A2 Near People flight:

1. IDs and certificate — Flyer ID, Operator ID, valid A2 CofC for A2 privileges
2. Aircraft eligibility — UK2/C2 <4 kg or legacy <2 kg for A2; mass correct after batteries, payload, and lights
3. VLOS — position, contrast, range, and airspace scan workable for the whole profile
4. Height — plan ≤120 m against closest surface reference, with margin
5. Airspace — outside FRZs and other restrictions, or permission obtained and conditions understood
6. People distances — A2 30 m / 5 m / 50 m rules (detailed in the separation chapter) and no intentional overflight of uninvolved people
7. Night — green flashing light fitted, tested, and left on if operating at night
8. No dangerous goods / no dropping articles
9. Privacy / nuisance considered in the flight plan and camera use
10. Landowner permission for take-off and landing site

If any line fails, you do not “partially comply.” You change the plan or you do not fly.