Visual Line of Sight (VLOS) Rules for Drone Pilots

Par Équipe UAV Meteo · Mis à jour le 24/09/2026 · 8 min de lecture

Almost every recreational and most commercial drone flights in Europe, the UK and the US must be flown within visual line of sight (VLOS). The rule is short, but pilots often read it as "as long as I could find it again if I looked." That is not what the regulations say. This guide sets out what the three most-used rulebooks actually require, and why weather is the factor that most often decides how far VLOS really reaches.

What the rules say

United States (FAA)

For commercial flights under Part 107, 14 CFR 107.31 requires the pilot, or a visual observer, to see the aircraft throughout the entire flight, with vision "unaided by any device other than corrective lenses", well enough to:

  1. know where the drone is;
  2. determine its attitude, altitude and direction of flight;
  3. watch the airspace for other traffic and hazards; and
  4. make sure it does not endanger people or property.

Recreational flyers operate under a separate law, 49 U.S.C. 44809. The FAA summarises its VLOS rule as keeping the drone in sight yourself, or using a visual observer who is co-located (physically next to you) and in direct communication with you.

European Union (EASA)

In the EU "open" category, the pilot must keep the drone in VLOS at all times. EASA's own FAQ lists only two exceptions: follow-me mode with a C0 or C1 drone or one under 250 g, and FPV flying with an unmanned-aircraft observer who is always looking at the drone and standing alongside the pilot.

United Kingdom (CAA)

The UK Drone and Model Aircraft Code says that you, or an observer, must keep the drone in direct sight and have a full view of the surrounding airspace at all times. If you fly by FPV, you must have an observer who stands next to you, can see the drone directly and can talk to you during the flight.

The three rulebooks are worded differently but agree on the essentials: your own eyes (glasses and contact lenses allowed), all the time, well enough to avoid a collision.

What "unaided" rules out

  • The live video on your phone or goggles. The camera shows what is in front of the drone, not what is approaching from the side or above. It is not VLOS under any of the three rulebooks.
  • Binoculars and zoom cameras as the way you keep track of the drone.
  • The map dot and telemetry. Knowing the drone's GPS position is not the same as seeing it.

Glancing at the screen to frame a shot is normal. What matters is that you look back at the drone and not let it become a dot you have lost.

Seeing it is not the same as flying VLOS

The FAA wording is the most useful test even outside the US: can you tell the drone's attitude and direction of travel, and could you see a helicopter coming towards it in time to react? A drone you can just about detect as a speck against the sky usually fails that test.

In practice, the distance at which you can do this depends on:

  • Size and colour. A sub-250 g drone is far harder to follow than a large enterprise quadcopter. Grey airframes vanish against an overcast sky; dark ones vanish against trees.
  • Background. A drone is easier to see against a clear sky than against a hillside, a forest or a city skyline.
  • Obstacles. Flying behind a building, a treeline or a ridge breaks line of sight, even if the drone is only 50 m away.
  • The weather, covered below.

None of the three rulebooks gives a fixed distance for VLOS in the open or recreational categories. The limit is whatever distance at which you can still meet the requirements above, and for small drones that is often much less than pilots expect.

How weather shrinks your line of sight

This is where a forecast becomes part of staying legal, not just staying safe.

  • Haze, mist and fog. Reduced visibility is the obvious one. The FAA sets a hard floor for Part 107 flights: at least 3 statute miles (about 4.8 km) of flight visibility from the control station (14 CFR 107.51). UAV Meteo's Visibility card uses a similar threshold: with the standard drone profile it shows Good from 8 km, Caution from 5 to 8 km, and Not suitable below 5 km.
  • Low cloud. Part 107 also requires the drone to stay at least 500 ft below clouds and 2,000 ft horizontally from them. Under a low cloud base a drone climbing towards the cloud becomes hard to see long before it reaches it. The Cloud Cover card shows how much of the sky is covered.
  • Low sun. Flying towards the sun around sunrise and sunset makes it almost impossible to keep a drone in view. Plan the flight so the sun is behind or to the side of you; our Golden Hour tool shows where the sun will be.
  • Dusk and night. In the US, flying during civil twilight or at night requires anti-collision lighting visible for at least 3 statute miles (14 CFR 107.29). In the EU, drones with a class label must have their green flashing light switched on when flying at night. Lights help you see where the drone is; they do not make its attitude any easier to judge.
  • Rain and snow. Precipitation cuts visibility and makes the drone harder to pick out. See can you fly a drone in the rain.

Using an observer properly

An observer is how FPV pilots stay legal, and a sensible extra for anyone flying near obstacles or busy airspace. The rules above expect the observer to:

  • stand next to the pilot, not at the far end of the site;
  • keep their eyes on the drone and the sky around it, not on the screen;
  • be briefed beforehand on what to call out, such as other aircraft, birds, people walking into the area or the drone approaching an obstacle; and
  • be able to speak to the pilot instantly.

An observer does not extend how far you can fly beyond their own line of sight. Flights beyond visual line of sight (BVLOS) need specific authorisation: a Part 107 waiver in the US, and the "specific" category in the EU and UK.

A pre-flight VLOS check

  1. Check visibility, cloud and precipitation for your flight time on UAV Meteo.
  2. Look at the site. Where will trees, buildings or terrain block your view? Plan the flight path around them.
  3. Note where the sun will be during the flight.
  4. Decide on a turn-back distance for your drone and today's conditions, and stick to it rather than flying until you lose sight.
  5. If you lose sight, stop and hover. Use the map and the drone's heading to turn it back towards you, and fly it home until you can see it again. If you still cannot find it, use Return-to-Home.

The pre-flight checklist covers VLOS together with the other checks before takeoff.

FAQ

Can I wear sunglasses while flying?

Generally yes. Sunglasses don't magnify or relay the image, so regulators treat them like ordinary vision. Many pilots find polarised lenses make it harder to read their screen, so test yours first.

Is there a maximum distance for VLOS?

Not a fixed one in the open or recreational categories. The limit is set by your ability to see the drone well enough to avoid collisions. The separate height limits are 120 m in the EU and UK, and 400 ft above ground in the US.

Can I fly FPV on my own?

Not under standard EU, UK or US recreational rules. All three require an observer next to you who keeps the drone in direct sight.

Does follow-me mode need VLOS?

In the US, yes. In the EU, follow-me mode is one of the two exceptions, but only for C0 or C1 drones or those under 250 g in the open category. Check your national rules before relying on it.

Sources

This guide summarises the rules for planning. It is not legal advice: always check the current rules of the country you fly in. See our Airspace page for no-fly zones.