010 Air Law topic guide
Airspace Classes A to G
SERA divides airspace into seven classes, A through G, and every one of those letters carries a fixed bundle of answers: whether VFR flight is allowed at all, what separation air traffic control provides, and what information a pilot can expect to receive. Learn the table cell by cell and it feels like thirty unrelated facts. Learn it as one sliding scale and most of the table falls out for free.
The scale runs from the most controlled to the least. Class A permits IFR only, Classes B to E mix IFR and VFR under progressively lighter service, and Classes F and G are uncontrolled. Move along that scale one class at a time and only one or two things change at each step, which is a far easier fact to hold in memory under exam pressure than the full grid taken all at once.
Controlled versus uncontrolled, and where VFR is allowed
Class A stands alone as IFR-only controlled airspace. VFR flight is barred there regardless of visibility, cloud clearance, or pilot qualification, so any option describing VFR minima inside Class A is wrong before you even check the numbers. Classes B, C, D and E are controlled and accept both IFR and VFR traffic, though each attaches different conditions to the VFR flight.
Classes F and G are uncontrolled: no clearance is required to enter either one, though a flight plan and, depending on the state and the flight rules used, a listening watch can still apply. The single break worth memorising is this: A through E is controlled airspace, F and G is not, and VFR is excluded only in Class A.
Separation and information services, top to bottom
Read the classes as a ladder of shrinking service. Classes A and B both give every flight full separation from every other flight, VFR included. Class C separates IFR flights from other IFR and from VFR, but a VFR flight only receives traffic information, not separation, from other VFR flights. Class D separates IFR flights from other IFR only; VFR flights receive traffic information about everything else in the airspace but no separation at all, not even from IFR traffic. Class E keeps separation for IFR from IFR only, and gives traffic information to all flights as far as practicable, with VFR flights normally needing no clearance to be there.
Classes F and G drop separation entirely. Class F still offers an advisory service to IFR traffic where practicable, on top of a flight information service given to everyone. Class G gives flight information only, and the responsibility for keeping clear of other traffic sits entirely with the pilot.
- Class A/B: separation given to every flight, VFR included in B
- Class C: IFR separated from IFR and VFR; VFR only gets traffic information on other VFR
- Class D: IFR separated from IFR only; VFR gets traffic information but no separation at all
- Class E: IFR separated from IFR only; traffic information as far as practicable for all
- Class F: uncontrolled, advisory service for IFR, flight information for everyone
- Class G: uncontrolled, flight information only, self-separation
The speed limit that cuts across class boundaries
A separate rule rides underneath the class table: below the commonly examined threshold of FL100 (10000 feet), aircraft are typically limited to 250 knots indicated airspeed, a limit aimed squarely at keeping closing speeds survivable in a see-and-avoid environment. The exam trap is assuming this speed limit only bites in uncontrolled airspace, or that it does not apply to fast jet aircraft descending through that level. It applies on the altitude threshold, not on the class of airspace or the type of aircraft.
Worked example
Worked example: matching services to the class
Not quite. The correct answer is B.
Correct answer: B
- A. In Class B every flight, VFR included, is separated from every other flight, so VFR-to-VFR separation also applies there, which is more service than the stem describes.
- B. Correct. In Class C, VFR flights are separated from IFR traffic but only receive traffic information, not separation, from other VFR flights, matching both parts of the stem exactly.
- C. In Class D, VFR flights are not separated from IFR traffic either; they only receive traffic information on everything. The stem specifically requires IFR-to-VFR separation, which Class D does not provide.
- D. Class E only guarantees IFR-to-IFR separation. A VFR flight there gets traffic information where practicable and no guaranteed separation from IFR traffic at all.
Step by step
- Identify what the stem requires: a VFR flight separated from IFR traffic, but not from other VFR traffic, which is a mixed level of service.
- Compare Classes B through E on exactly that split: Class B separates everyone from everyone, while Classes D and E give VFR flights no separation from IFR at all.
- Class C sits between those extremes: VFR is separated from IFR, but only informed, not separated, from other VFR.
- Class C matches both parts of the stem, so it is the answer.
Common mistakes
Assuming Class D gives VFR some separation because ATC is still involved
In Class D, ATC only separates IFR from other IFR. A VFR flight there receives traffic information on everything else but zero guaranteed separation, and treating any ATC involvement as automatic separation costs the mark on this exact distinction.
Treating Class F and Class G as identical because both are uncontrolled
Class F still offers an advisory service to IFR traffic where practicable, which Class G does not provide at all. Collapsing the two into one uncontrolled category erases a difference the exam tests directly.
Forgetting that VFR is barred entirely in Class A
Any option that describes VFR minima or VFR traffic inside Class A is wrong regardless of what numbers it quotes, because Class A is IFR only. Spotting this early can eliminate an option before doing any other reasoning.
Related topic guides
Practise Air Law the way the exam asks it.
SkyStudy turns Airspace Classes A to G and every other Air Law topic into exam-style practice questions with explanations, spaced repetition, and timed mock exams. Free to start.
Important information
This page is general educational information for student pilots and may be out of date.
Aviation rules, training requirements, costs, medical standards, and exam details change over time and vary by country, authority, and training organisation, so details here may no longer be current or may differ in your case.
Always confirm the current details with your approved training organisation (ATO) and national aviation authority before relying on them.
SkyStudy is an independent study aid, is not affiliated with EASA or any aviation authority, and does not guarantee any exam or licence outcome.
Last reviewed July 2026