Special VFR is the rule that lets you slip into or out of a busy control zone when the weather is too poor for ordinary visual flight but not so bad that flying carefully is unreasonable. It is a clearance you ask for, and it comes with strings attached.
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.
What special VFR actually is
Inside a control zone, a VFR flight normally has to meet the visual meteorological conditions (VMC) for that airspace: a minimum flight visibility and a set distance from cloud. When the weather dips below those minima, ordinary VFR is no longer legal there. Special VFR (SVFR) is the controlled exception. It is, in the words of ICAO Annex 2, a VFR flight cleared by air traffic control to operate within a control zone in meteorological conditions below VMC. You request it, ATC weighs it against other traffic, and if it is granted you fly to a different, reduced set of conditions.
The point of it is access. A control zone usually wraps the airspace around a busy aerodrome, and a marginal day would otherwise trap a VFR pilot outside it, or inside it, with no legal way through. SVFR opens a narrow, supervised door, while keeping the responsibility for terrain and obstacle clearance firmly on the pilot.
The conditions in Europe: SERA.5010
Under SERA.5010, a special VFR flight in a control zone is flown to these conditions, which fall partly on the pilot and partly on ATC.
The pilot must:
- remain clear of cloud and in sight of the surface;
- keep flight visibility at not less than 1,500 m, or not less than 800 m for helicopters;
- fly at an indicated airspeed of 140 kt or less, so there is time to see and avoid other traffic and obstacles in the reduced visibility.
Air traffic control will only issue the clearance:
- by day, unless the competent authority permits otherwise;
- when the ground visibility is at least 1,500 m (800 m for helicopters);
- when the cloud ceiling is not below about 600 ft.
The clear-of-cloud-and-in-sight-of-the-surface rule is the heart of it. You are giving up the comfortable cloud-separation buffer of normal VMC, so you keep the ground in sight and the cloud out of your way by eye, at a speed slow enough to react.
The conditions in the United States: 14 CFR 91.157
The FAA frames the same idea differently in 14 CFR 91.157. A special VFR clearance applies in the surface area of controlled airspace below 10,000 ft MSL, and:
- the aircraft must remain clear of clouds;
- flight visibility must be at least 1 statute mile, and if ground visibility is reported it too must be at least 1 statute mile;
- at night, between sunset and sunrise, the pilot must hold an instrument rating and the aircraft must be equipped for instrument flight.
Helicopters are treated more leniently and may operate clear of clouds below the 1 statute mile visibility under the special provisions. As in Europe, a clearance is required, and ATC may refuse or delay it for traffic.
The two systems side by side
The same flight, in the same weather, is judged on different numbers depending on where you are. SERA asks for 1,500 m flight visibility, clear of cloud and in sight of the surface, at 140 kt or less, normally by day. The FAA asks for clear of clouds and 1 statute mile, which is about 1,600 m, with an instrument rating and an IFR-capable aircraft required at night. Both replace the normal VMC cloud-separation minima with a clear-of-cloud rule at reduced visibility; the SERA version adds the explicit in-sight-of-the-surface and speed conditions, and the FAA version adds the night instrument requirement. Carry one system's figures into the other's airspace and you will misjudge what you are cleared to do.
A clearance, not a right: why ATC may refuse
It is worth dwelling on the word clearance. A special VFR flight has to be fitted into the controlled-airspace traffic picture, and inside a control zone the controller is usually separating instrument traffic that is flying approaches and departures in the same poor weather. Slotting a slow VFR aircraft, picking its way along clear of cloud, into that flow is not always possible, so the controller may refuse the request, delay it, or grant it only along a specific route, level or time window. Many busy zones apply a one-in, one-out rule, allowing a single special VFR flight at a time, precisely because keeping it apart from the instrument traffic in a small volume of airspace is demanding.
It also helps to be clear about who is responsible for what. Under special VFR the controller provides separation from other known traffic, but you, the pilot, keep responsibility for terrain and obstacle clearance and for staying clear of cloud and in sight of the surface. That division is the same reason the rule insists on the slow speed and the visual contact with the ground: you are doing the see-and-avoid for terrain yourself, at a pace that gives you time.
Set against normal flight, the concession is narrow. Ordinary VFR in a control zone of that class needs around 5 km flight visibility while clear of cloud and in sight of the surface. Special VFR keeps the clear-of-cloud-and-in-sight-of-the-surface part but drops the visibility floor to 1,500 m (800 m for helicopters) and adds the 140 kt limit. You are not being allowed to fly in cloud; you are being allowed to fly in poorer visibility, slowly, by eye, under a clearance.
A worked example
A control zone is reporting visibility of 2,000 m with broken cloud at 700 ft. You want to route through it under VFR. The normal VMC minimum for that class of control zone is a flight visibility of 5 km while clear of cloud and in sight of the surface, so at 2,000 m you cannot fly ordinary VFR there: the visibility is below the VMC requirement.
You request special VFR. Under SERA.5010 the controller can clear it, because the ground visibility of 2,000 m is above the 1,500 m floor and the ceiling at 700 ft is above the 600 ft floor. Cleared, you fly clear of cloud and in sight of the surface, keep your speed to 140 kt or less, and accept that the responsibility for staying above the terrain and obstacles inside the zone is yours, not the controller's.
Now run the same weather in the United States. Under 14 CFR 91.157 the controller can issue special VFR if you remain clear of clouds with at least 1 statute mile of flight visibility; the reported 2,000 m is just over 1 statute mile, so it qualifies. But if it were night, you would also need an instrument rating and an IFR-equipped aeroplane before the clearance was available, a condition SERA states differently. Same sky, two rule sets, two slightly different answers.
Common pitfalls
- Treating special VFR as a right. It is a clearance you request and ATC may refuse or delay; you do not simply elect it.
- Forgetting whose job terrain clearance is. Under SVFR you keep clear of obstacles and terrain visually; the controller is separating traffic, not flying the aircraft.
- Carrying the figures across authorities. SERA's 1,500 m and 140 kt are not the FAA's 1 statute mile and night instrument rule. Use the rule for the airspace you are in.
- Assuming it is available at night. SERA treats it as a daytime clearance by default, and the FAA only allows it at night with an instrument rating and an IFR-equipped aircraft.
- Confusing low visibility with cloud separation. SVFR lets you fly at reduced visibility, but you are still clear of cloud and in sight of the surface, not picking your way through it.
In Pilot EFB
Pilot EFB is a study and planning companion for the visual flight rules and the control-zone weather minima that special VFR sits beneath, alongside your decoded METAR, your VFR minima and the rest of your offline-first briefing. It does not request a clearance, judge whether the weather qualifies, or grant special VFR, and the binding conditions are those in the current rules and the clearance you actually receive. Pilot EFB is not a certified Electronic Flight Bag, so treat it as a study and planning aid and fly from your official source of record.