Flying visually is only legal when you can actually see, and the rules turn "enough to see" into specific numbers that, frustratingly for the traveller, change as you cross a border.
This is general educational information, not operational, legal, or regulatory advice. Rules differ by authority and change over time. Always verify against current official sources and follow your operator's approved procedures.
The ICAO baseline
Visual flight depends on the pilot seeing and avoiding terrain, obstacles, and other aircraft, so the rules set a minimum flight visibility and a minimum distance from cloud, together called the visual meteorological conditions (VMC) minima. The international baseline is ICAO Annex 2 (Rules of the Air), which establishes both the VMC minima and the table of cruising levels by direction. Each authority then writes its own figures, and because they differ in both value and units, you must attribute each to its authority and never treat one as universal.
VMC minima under EASA
In Europe, the Standardised European Rules of the Air (SERA), in SERA.5001, set the VMC minima in kilometres and metres. In summary, and subject to the full table:
- At and above about 3050 m (roughly FL100): flight visibility 8 km, and a distance from cloud of 1500 m horizontally and 300 m (1000 ft) vertically.
- Below about 3050 m: flight visibility 5 km, with the same 1500 m and 300 m distances from cloud.
- At low level (at or below 900 m / 3000 ft above mean sea level, or 300 m / 1000 ft above terrain, whichever is higher): in Classes F and G, 5 km visibility, which may be reduced under defined low-speed conditions, clear of cloud and with the surface in sight; in Classes A to E, the same 5 km visibility but still 1500 m horizontally and 300 m vertically from cloud.
The exact bands, the airspace classes they apply to, and the reductions are set out in SERA.5001, and some States, including the United Kingdom, apply national low-level provisions on top, so read the current table for where you fly.
VMC minima under the FAA
In the United States, 14 CFR 91.155 sets the minima in statute miles and feet, and they vary by airspace class and altitude. Some headline cases, with the full matrix in the regulation and the FAA AIM Table 3-1-1:
- Class B: 3 statute miles visibility and clear of clouds.
- Class C, D and E below 10,000 ft MSL: 3 statute miles, with 500 ft below, 1000 ft above, and 2000 ft horizontally from cloud.
- Class G, day, at or below 1200 ft above the surface: 1 statute mile and clear of clouds (with different, larger figures at night).
- At and above 10,000 ft MSL (Class E, and Class G more than 1200 ft above the surface): 5 statute miles, with 1000 ft below, 1000 ft above, and 1 statute mile horizontally from cloud.
Class A is instrument flight only, so there are no VFR minima for it. Note how different the structure is from the EASA table: different units, different airspace bands, and a separate night treatment in uncontrolled airspace.
VFR cruising levels
Above a certain height, opposite-direction VFR traffic is kept apart vertically by choosing the cruising level according to the direction of flight, the semicircular rule.
In the United States, 14 CFR 91.159 requires that, in level cruising flight more than 3000 ft above the surface, you fly:
- on a magnetic course of 0 to 179 degrees, an odd thousand plus 500 ft (3500, 5500, 7500, and so on);
- on a magnetic course of 180 to 359 degrees, an even thousand plus 500 ft (4500, 6500, and so on).
Europe uses the equivalent table in SERA and ICAO Annex 2, Appendix 3, splitting the same way at the 000 to 179 and 180 to 359 boundary but keyed to magnetic track rather than the FAA's magnetic course, and with its own level values; consult SERA Appendix 3 or ICAO Annex 2 Appendix 3 for the exact levels rather than carrying the US figures across.
Common pitfalls
- Mixing the units. EASA is kilometres and metres; the FAA is statute miles and feet. The numbers look similar and mean different things.
- Forgetting that minima depend on airspace and altitude. "VFR minima" is not one number; it changes with the class you are in and how high you are.
- Reading "clear of clouds" as "any distance". Class B and low-level Class G allow clear-of-cloud flight, but most controlled airspace below 10,000 ft demands specific separations.
- Using magnetic heading, not course, for the cruising rule, and remembering it only applies above 3000 ft AGL.
In Pilot EFB
Pilot EFB shows the decoded METAR and TAF, so the reported visibility and cloud are spelled out for you in plain language with the raw text kept alongside. It does not decide whether conditions meet the VFR minima for your airspace, and it is not a certified Electronic Flight Bag. It is a study and planning aid: judge the minima against the current regulation for the airspace you will fly in, and brief from your official meteorological source. Saved weather stays readable offline; pulling a fresh observation needs a connection.