VectorEFB
Menu
Request access

Learning hub · Air Law · Lesson 2

Airspace classes and VFR weather minima

Two questions decide whether a VFR flight is legal: what class of airspace are you in, and is the weather good enough for that class and height? This lesson answers both, using the European rules (SERA).

About 13 minutes, plus the quiz. Part of Air Law. It builds on rules of the air and right of way.

1. The classes, seen from the VFR seat

Airspace is divided into classes A to G. The class sets who may fly there, whether you need a clearance and what service you get. SERA (Regulation (EU) No 923/2012, section 6) describes them. For a VFR pilot the useful summary is:

ClassVFR flights?ATC clearance for VFR?What you get as a VFR pilot
ANo, IFR onlyNot applicableNot open to VFR
BYesYesSeparation from all other flights
CYesYesSeparation from IFR flights; traffic information on other VFR flights
DYesYesTraffic information on all other flights; avoidance advice on request
EYesNoTraffic information as far as practical
FYesNoFlight information service if you ask
GYesNoFlight information service if you ask

In classes B, C and D you must have continuous two-way radio contact and a clearance before you enter. In classes C to G, SERA also sets a speed limit of 250 kt indicated airspeed below 3,050 m (10,000 ft) AMSL for VFR flights. Each State chooses which classes it uses, so the AIP tells you what exists in Romania.

2. VFR weather minima

VFR means you stay in visual meteorological conditions (VMC). SERA.5001 gives the minimum flight visibility and distance from cloud. The table is SERA Table S5-1, simplified; its figures are the same in the current consolidated text.

Height bandClassesFlight visibilityDistance from cloud
At and above 3,050 m (10,000 ft) AMSLB to G8 km1,500 m horizontally, 300 m (1,000 ft) vertically
Below that, and above 900 m (3,000 ft) AMSL or 300 m (1,000 ft) above terrain, whichever is higherB to G5 km1,500 m horizontally, 300 m (1,000 ft) vertically
At and below 900 m (3,000 ft) AMSL or 300 m (1,000 ft) above terrain, whichever is higherB to E5 km1,500 m horizontally, 300 m (1,000 ft) vertically
Same height bandF and G5 kmClear of cloud and with the surface in sight

Class A appears in the SERA table for guidance only and does not mean VFR is accepted there. Where the transition altitude is lower than 3,050 m, SERA uses FL 100 instead of 10,000 ft. In classes F and G in the lowest band, the competent authority can allow a reduced visibility of not less than 1,500 m for aircraft at 140 kt IAS or less. Separately, SERA.5005 forbids VFR take-off or landing at an aerodrome in a control zone, or entering its traffic zone or circuit, when the reported ceiling is below 450 m (1,500 ft) or the ground visibility below 5 km, unless you have a clearance from ATC (special VFR, in practice).

These are the European minima. The Romanian AIP is the document that governs flights in Romania, and it can add to or restrict what SERA says. Always check it.

Worked example (invented figures). You fly at 2,500 ft AMSL in class G. The ground is 400 ft above sea level. The lower limit of the middle band is the higher of 3,000 ft AMSL and 1,400 ft AMSL (terrain plus 1,000 ft), which is 3,000 ft AMSL. You are below that, so you are in the lowest band. In class G that means 5 km flight visibility, clear of cloud, with the surface in sight.

3. Special VFR

A special VFR clearance lets you fly inside a control zone in weather below the normal VFR minima. SERA.5010 sets the conditions.

  • You need an ATC clearance. You cannot decide to fly special VFR by yourself.
  • You stay clear of cloud with the surface in sight, with flight visibility of at least 1,500 m, at 140 kt IAS or less.
  • It is by day only, unless the competent authority allows otherwise. ATC will not issue it for take-off, landing or entering the circuit when the ground visibility is below 1,500 m or the ceiling is below 180 m (600 ft).

It is a tool for trained pilots in marginal weather, not a way to push on. Whether it is available at a given aerodrome is a matter for the AIP and for ATC.

4. Controlled or uncontrolled

In practice, think of two groups. In controlled airspace (classes B, C and D for VFR) you need a clearance and two-way radio. In class E you may enter without a clearance, but IFR traffic is under control there, so keep a lookout and listen. In classes F and G nobody separates you from other traffic, and you remain responsible for seeing and avoiding it.

SERA also provides for a radio mandatory zone (RMZ) and a transponder mandatory zone (TMZ), set by the competent authority. In an RMZ you keep a listening watch and make an initial call before entering. In a TMZ you carry and operate a transponder. Both are published in the AIP, and both can sit inside otherwise uncontrolled airspace.

5. Reading the class on a chart

A VFR chart shows airspace as shapes with labels. For each block, read three things: the class letter, the lower and upper limits (in feet AMSL, feet above ground or flight level) and the name of the zone or area. Boundaries often differ by height, so a circle on the ground may become a larger ring higher up. The chart legend explains the line styles and colours, which differ between chart series, so read the legend of the chart in your hand.

This is training material. A chart can be out of date. Use the current AIP and charts, check NOTAMs, and follow your school’s procedures. The figures above were checked against the current consolidated SERA (EASA Easy Access Rules, August 2025); later amendments and national rules may still differ.

6. Try it yourself

Work each one out on paper first, then open the answer to compare. The numbers are invented.

  1. You plan to fly at 4,000 ft AMSL in class D airspace. The ground below is 2,500 ft AMSL. Which visibility and cloud clearance apply?

    Show the answer
    1. Find the lower edge of the middle band: the higher of 3,000 ft AMSL and 1,000 ft above terrain, which is 2,500 + 1,000 = 3,500 ft AMSL.
    2. 3,500 ft is higher than 3,000 ft, so the edge is 3,500 ft AMSL.
    3. At 4,000 ft you are above it and below 10,000 ft, so the middle band applies.
    4. Answer: 5 km flight visibility, 1,500 m horizontally and 300 m (1,000 ft) vertically from cloud. Also remember you need a clearance in class D.

  2. An airfield has a control zone. The reported weather is ceiling 1,200 ft and ground visibility 8 km. You hold no ATC clearance (special VFR). May you enter the circuit under normal VFR?

    Show the answer
    1. SERA.5005 sets the limit for the circuit of a controlled aerodrome: ceiling not below 450 m (1,500 ft) and ground visibility not below 5 km.
    2. The ceiling of 1,200 ft is below 1,500 ft, even though the visibility is fine.
    3. Answer: no. You would need a clearance from ATC (special VFR, in practice), if it is available and the weather meets its conditions.

  3. ATC is asked for a special VFR clearance to land at its aerodrome. The ground visibility is 2,000 m and the ceiling is 500 ft. Under the SERA conditions, can ATC give it?

    Show the answer
    1. Convert the ceiling: 500 ft is about 152 m.
    2. Under SERA.5010, ATC does not issue it for landing when the ceiling is below 180 m (600 ft) or the ground visibility is below 1,500 m.
    3. The visibility is enough (2,000 m is above 1,500 m), but the ceiling of 152 m is below 180 m.
    4. Answer: no, not under the SERA conditions. The AIP may add other limits, so ATC’s decision stands.

7. Watch

A video on VFR, IFR and the airspace classes used in Europe, a good fit for this lesson. Details such as which classes a country uses vary, so check the AIP.

Open on YouTube if the player does not load. Not made by VectorEFB; check what you learn against your flying school’s material and your instructor.

More to watch

A second explanation of the airspace classes. This video is American, so wording, the classes in use and the weather minima differ from European (ICAO/EASA) practice; use it for the idea, not for the numbers.

Open on YouTube if the player does not load. Not made by VectorEFB.

8. Check yourself

Five original practice questions. Answer them, press Check answers and read each explanation.

1. In which class of airspace is VFR flight not permitted?

Class A is for IFR flights only. Classes B to G allow both VFR and IFR flights.

2. You are VFR in class G at 2,000 ft AMSL over flat ground at sea level. What does SERA require at that height?

Below 900 m (3,000 ft) AMSL or 300 m above terrain, whichever is higher, class G needs 5 km flight visibility, clear of cloud, surface in sight.

3. What is needed before a VFR flight enters class C airspace?

In classes B, C and D, VFR flights are subject to ATC clearance and need continuous air-ground voice communications.

4. In SERA, which of these is a condition for ATC to give a special VFR clearance?

SERA.5010 says ATC does not issue it for take-off, landing or the circuit when the ground visibility is below 1,500 m or the ceiling is below 180 m (600 ft); it is by day unless the authority allows otherwise.

5. Which document governs the airspace and weather rules for a flight in Romania, on top of SERA?

SERA gives the common European rules. The national AIP publishes the airspace, procedures and any national differences.

Next: licences, medicals and privileges. Back to the learning hub.

For training and situational awareness only. Not certified for navigation. Always use official charts, the AIP, NOTAMs and a proper weather briefing for real flights.