Rules of the air: definitions and applicability
Learning objectives
- State to which flights and which people SERA applies, and what happens over the high seas and outside the EU.
- Explain how the general rules, local provisions and VFR or IFR combine, and state the responsibility and authority of the pilot-in-command.
- Distinguish manoeuvring area, movement area and apron, and identify what counts as air traffic and as an air traffic service.
- State the rule on psychoactive substances and which substances it counts.
The idea
Every flight needs a shared rulebook, or two pilots meeting in the same sky would each play by their own habits. In Europe that rulebook is one common set of rules of the air. It follows your aircraft's registration and the airspace you fly in. One person is always answerable for obeying it: the pilot-in-command, whoever is holding the controls. Before you can use any rule you also need exact meanings for everyday words such as "aerodrome", "air traffic" or "clearance", because the rules and the exam use them precisely.
Where the rules come from and who they bind
SERA, the Standardised European Rules of the Air, is the EU's common set of rules of the air. It is the EU's transposition of ICAO's rules of the air, and inside the EU it is the rule in force. It covers general air traffic.
SERA applies to airspace users and aircraft in general air traffic that either operate into, within or out of the EU, or carry the nationality and registration marks of an EU Member State, wherever they fly. The second half has a limit: SERA applies as long as it does not conflict with the rules of the State whose territory is overflown.
In practice, an EU-registered aeroplane flying outside the EU still follows SERA unless the local State's rules say otherwise, and then the local rules win. A non-EU aeroplane flying in the EU follows SERA.
Describe this figure
The flowchart starts at "Your flight". If it goes into, within or out of the EU, SERA applies. If not, the next question is whether the aircraft is EU-registered: yes means SERA applies, unless the State you overfly has a conflicting rule, which then wins; no means the local State's rules apply. Three dotted boxes list exceptions: over the high seas ICAO Annex 2 applies with no exceptions; model and toy aircraft are outside SERA; some State flights are flown as operational air traffic, outside SERA.
The flowchart starts at "Your flight". The first question is "Into, within or out of the EU?" and a yes leads straight to SERA. A no leads to "Is the aircraft EU-registered?", where a yes also leads to SERA, with a note that the overflown State's rules win if they conflict. Three side boxes cover the special cases: over the high seas, ICAO's rules apply with no exceptions; model and toy aircraft are outside SERA and fall under national rules; and certain State flights flown as operational air traffic are outside SERA.
Some details:
- The rules bind more than pilots. They also apply to competent authorities, air navigation service providers, the Network Manager, aerodrome operators and ground personnel engaged in aircraft operations.
- SERA does not apply to model aircraft and toy aircraft. Member States must have national rules so that these are flown in a way that minimises hazards to civil aviation, persons, property and other aircraft.
- Over the high seas, the rules of ICAO Annex 2 apply without exception.
- Member States must ensure compliance with SERA.
- A competent authority is the authority a Member State designates to ensure compliance with SERA.
Exemptions and State choices
Competent authorities may grant exemptions from any SERA requirement for public-interest activities and the training for them: police and customs, traffic surveillance and pursuit, environmental control by or for public authorities, search and rescue, medical flights, evacuations, fire fighting, and security of flights of heads of State, Ministers and comparable officials. The authority must inform EASA within two months of approving an exemption.
Guidance adds that these exemptions are for operations of sufficient public interest. Everyday flexibility is done differently: many SERA points say "as permitted by the competent authority" or "unless otherwise specified by the competent authority". Some State operations may be flown as operational air traffic (OAT) and are then entirely outside SERA.
Anything SERA leaves to a competent authority's decision must be published by the Member State in its AIP, the Aeronautical Information Publication. For you, that means State options such as night VFR, reduced visibility or the datum for VFR cruising levels are found in that State's AIP. An AIP is a publication issued by or with the authority of a State, containing aeronautical information of a lasting character that is essential to air navigation.
When planning a flight to another State, remember that you are bound by SERA but also by that State's published choices and local rules. Read the destination's AIP and the NOTAMs before you go. A NOTAM is a notice distributed by telecommunication about the establishment, condition or change of any aeronautical facility, service, procedure or hazard that flight operations personnel need to know in time.
Layers of rules, and who answers for them
An aircraft in flight, on the movement area of an aerodrome or at an operating site must comply with the general rules and the applicable local provisions. In flight it must, in addition, comply with either the visual flight rules or the instrument flight rules.
Think of it as layers. The general rules apply always, including on the ground. Local provisions come next. On top, in flight only, sits exactly one of VFR or IFR. Local provisions include, for example, local aerodrome regulations published in the AIP, such as a requirement to operate the transponder on the movement area. VFR is taught on page 010-05-03.
Being in good weather does not oblige you to fly VFR: a pilot may elect to fly IFR in VMC, or the competent authority may require it.
The pilot-in-command
The pilot-in-command (PIC) is the pilot designated by the operator, or in general aviation by the owner, as being in command and charged with the safe conduct of the flight.
- The PIC is responsible for operating the aircraft in accordance with SERA, whether or not they are manipulating the controls.
- The PIC may depart from the rules only in circumstances that make the departure "absolutely necessary in the interests of safety".
- The PIC has final authority as to the disposition of the aircraft while in command.
When two licensed pilots share a flight, agree before engine start who is PIC. Responsibility does not depend on who holds the controls.
Before you fly
Before beginning a flight, the PIC must become familiar with all available information appropriate to the intended operation. For flights away from the vicinity of an aerodrome, and all IFR flights, pre-flight action must include a careful study of current weather reports and forecasts, taking into account fuel and energy requirements and an alternative course of action in case the flight cannot be completed as planned.
For flights away from the vicinity of an aerodrome, pre-flight action includes a careful study of current weather reports and forecasts, taking into account fuel and energy requirements and an alternative course of action in case the flight cannot be completed as planned.
Words the rules depend on: aerodrome areas
Start with the wide words. An aircraft is any machine that can get support in the atmosphere from reactions of the air other than reactions of the air against the earth's surface, so a hovercraft is not an aircraft. An aeroplane is narrower: a power-driven heavier-than-air aircraft that gets its lift in flight chiefly from aerodynamic reactions on surfaces that remain fixed under given flight conditions. Sailplanes are heavier-than-air but not power-driven, and rotorcraft get lift from rotors, so neither is an aeroplane.
An aerodrome is a defined area on land or water, or on a fixed, fixed off-shore or floating structure, including buildings, installations and equipment, intended to be used wholly or partly for the arrival, departure and surface movement of aircraft. An operating site is a site selected by the operator or pilot-in-command for landing, take-off and/or hoist operations. It need not be an aerodrome.
Inside the aerodrome, the terms nest:
- A runway is a defined rectangular area on a land aerodrome prepared for landing and take-off.
- A taxiway is a defined path on a land aerodrome for taxiing, linking one part of the aerodrome with another.
- Taxiing is movement of an aircraft on the surface of an aerodrome or operating site under its own power, excluding take-off and landing.
- An apron is a defined area for loading or unloading passengers, mail or cargo, fuelling, parking or maintenance.
- The manoeuvring area is the part of an aerodrome used for take-off, landing and taxiing, excluding aprons.
- The movement area is the part used for take-off, landing and taxiing, consisting of the manoeuvring area and the aprons.
- The landing area is the part of a movement area intended for landing or take-off.
Describe this figure
A plan view shows one runway, a parallel taxiway with two links and an apron. The runway and taxiways form the tinted manoeuvring area; the apron has its own tint; a dotted outline around both is the movement area. Two aircraft are in flight: one far away is air traffic only, one on approach is air traffic and aerodrome traffic. A taxiing aircraft is air traffic and aerodrome traffic. An aircraft parked on the apron is not air traffic.
The plan view shows one runway, a parallel taxiway with two links, and an apron with parked aircraft. The runway and taxiways are tinted as the manoeuvring area, the apron has a second tint, and a dashed outline around both is the movement area. An aircraft on the apron is labelled "not air traffic", while an aircraft rolling on the taxiway or in the air is.
Air traffic and aerodrome traffic
Air traffic is all aircraft in flight or operating on the manoeuvring area of an aerodrome. So an aeroplane parked on the apron is not air traffic, but the same aeroplane taxiing on a taxiway is. Aerodrome traffic is all traffic on the manoeuvring area plus all aircraft flying in the vicinity of the aerodrome; the circuit is taught on page 010-05-03.
Words the rules depend on: services and clearances
An air traffic service (ATS) is the generic term for flight information service, alerting service, air traffic advisory service and air traffic control service. The control service can be area, approach or aerodrome control.
Describe this figure
The root is "Air traffic services (ATS)". It has four branches: flight information service, alerting service, air traffic advisory service and air traffic control service. The flight information service gives advice and information for safe, efficient flights. The alerting service notifies organisations that need search and rescue. The air traffic control service prevents collisions and keeps traffic flowing in order. It splits into three: area control, provided by an area control centre; approach control, provided by an approach control unit; and aerodrome control, provided by an aerodrome control tower.
The tree has "Air traffic services" at the root with four branches: flight information service, alerting service, air traffic advisory service and air traffic control service. The control branch splits again into area control, approach control and aerodrome control.
- The air traffic control (ATC) service is provided to prevent collisions between aircraft, and on the manoeuvring area between aircraft and obstructions, and to expedite and maintain an orderly flow of air traffic. Terrain is not in the list.
- Flight information service (FIS) gives advice and information useful for the safe and efficient conduct of flights.
- The alerting service notifies the appropriate organisations about aircraft needing search and rescue aid, and assists them as required; it is taught on page 010-07-04.
- A flight information region (FIR) is airspace of defined dimensions in which FIS and the alerting service are provided.
- An ATC unit is the generic term for an area control centre, approach control unit or aerodrome control tower. An ATS unit is the generic term for an ATC unit, flight information centre, aerodrome flight information service unit or ATS reporting office.
An ATC clearance is authorisation for an aircraft to proceed under conditions specified by an ATC unit. It is often shortened to "clearance" and may be prefixed by taxi, take-off, departure, en route, approach or landing. An ATC instruction is a directive from ATC requiring a pilot to take a specific action.
Controlled airspace is airspace of defined dimensions in which ATC service is provided in accordance with the airspace classification. Guidance calls it a generic term covering Classes A, B, C, D and E. A control area is controlled airspace extending upwards from a specified limit above the earth, unlike a control zone, which starts at the surface. Classes are taught on page 010-07-01.
A controlled flight is any flight that is subject to an ATC clearance. A controlled aerodrome is one where ATC service is provided to aerodrome traffic. It is about the service, not the class of the airspace around it.
Say "clearance" and "instruction" carefully on the radio. A clearance permits something under stated conditions; an instruction requires an action.
Other words you will meet
- A flight plan is specified information provided to ATS units about an intended flight or portion of a flight; page 030-11-01 teaches the detail.
- Level is the generic term for the vertical position of an aircraft in flight: height, altitude or flight level.
- A flight level is a surface of constant atmospheric pressure related to the datum 1013.2 hPa and separated from other such surfaces by specific pressure intervals. Altimetry is taught on page 050-01-06.
- Track is the projection on the earth's surface of the aircraft's path, its direction usually in degrees from north: true, magnetic or grid.
- Heading is the direction in which the aircraft's longitudinal axis points, usually in degrees from north: true, magnetic, compass or grid.
- An obstacle is any fixed (temporary or permanent) or mobile object, or part of one, that is on an area for surface movement of aircraft, extends above a defined surface protecting aircraft in flight, or stands outside those surfaces but has been assessed as a hazard to air navigation.
- A mountainous area is an area of changing terrain profile where terrain elevation changes by more than 900 m (3 000 ft) within 18.5 km (10.0 NM).
- Traffic information is information from an ATS unit alerting a pilot to other known or observed traffic that may be close to the aircraft's position or intended route, to help the pilot avoid a collision.
Psychoactive substances
No safety-sensitive person may carry out their function while under the influence of any psychoactive substance that impairs human performance, and no such person may engage in any problematic use of substances. As a pilot, you are safety-sensitive: crew members are on the list, along with maintenance staff, aerodrome operations personnel, rescue and fire-fighting staff, people with unescorted access to the movement area, and air traffic controllers.
Safety-sensitive personnel must not perform their function under the influence of any psychoactive substance that impairs human performance, and must not engage in any problematic use of substances.
The word "psychoactive" is defined by a list: alcohol, opioids, cannabinoids, sedatives and hypnotics, cocaine, other psychostimulants, hallucinogens and volatile solvents. Caffeine and tobacco are excluded. Problematic use means use of one or more psychoactive substances by aviation personnel in a way that is a direct hazard to the user or endangers others' lives, health or welfare, or causes or worsens an occupational, social, mental or physical problem or disorder.
| Substance group | In the SERA definition? |
|---|---|
| Alcohol | Counted |
| Opioids | Counted |
| Cannabinoids | Counted |
| Sedatives and hypnotics | Counted |
| Cocaine | Counted |
| Other psychostimulants | Counted |
| Hallucinogens | Counted |
| Volatile solvents | Counted |
| Caffeine | Excluded |
| Tobacco | Excluded |
| SERA.2020 states the rule without any numerical limit: there is no alcohol figure on this page. Limits are taught on 040-04-04. | |
Describe this figure
The table has two columns, the substance group and whether it is in the SERA definition. Eight groups are counted as psychoactive: alcohol, opioids, cannabinoids, sedatives and hypnotics, cocaine, other psychostimulants, hallucinogens and volatile solvents. Two are excluded: caffeine and tobacco. A footer says that SERA.2020 states its rule without any numerical limit, so there is no alcohol figure here.
The table has two columns. "Counted as psychoactive" lists alcohol, opioids, cannabinoids, sedatives and hypnotics, cocaine, other psychostimulants, hallucinogens and volatile solvents. "Excluded" lists caffeine and tobacco. A footer says SERA sets no alcohol figure.
SERA gives this rule without any number. This page gives no numeric alcohol or substance limits; they are taught on page 040-04-04.
In the real world
Two pilots take turns flying a cross-country leg. Before start-up they agree who is the PIC for the whole flight, and the PIC checks weather, fuel and an alternative course of action before leaving the vicinity of the aerodrome. Responsibility stays with the PIC even during the other pilot's leg.
Exam traps
"SERA only applies inside EU airspace." It also applies to EU-registered aircraft anywhere, unless it conflicts with the rules of the State overflown.
"Movement area and manoeuvring area are the same." The manoeuvring area excludes aprons. The movement area is the manoeuvring area plus the aprons.
"An aeroplane parked on the apron is air traffic." Air traffic is aircraft in flight or on the manoeuvring area. The apron is not part of it.
"ATC keeps me clear of terrain." The ATC service prevents collisions between aircraft and, on the manoeuvring area, with obstructions. Terrain is not in the definition.
"A controlled flight is any flight in controlled airspace." It is any flight subject to an ATC clearance. A VFR flight in Class E without a clearance is not a controlled flight.
"SERA sets the legal alcohol limit." The rule contains no figure. It bans performing a safety-sensitive function while impaired. Caffeine and tobacco are not counted as psychoactive substances.
Explain it back
An EU-registered aeroplane is flown by two licensed friends from a Spanish aerodrome to a destination outside the EU. In your own words, which rules apply along the way, who is responsible if the pilot not at the controls spots a rule being broken, and what would you check in the AIP before leaving?
Self-check
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An aeroplane registered in an EU Member State is flying in the airspace of a State outside the EU. Which statement about the rules of the air is correct?mcq · easy
Show answer
SERA follows the registration of the aircraft as well as the airspace, so an EU-registered aeroplane keeps to it abroad. The limit is a conflict with the overflown State's rules, where the local rules win. The first option wrongly ties SERA to EU airspace only. The third ignores the conflict limit. The fourth is wrong because SERA still applies to the aeroplane.
Reference: SERA.2001(a), (b); Reg. (EU) No 923/2012 Article 1(2)
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A small aeroplane is parked at its stand on the apron with the engine stopped. Which statement is correct?mcq · medium
Show answer
The movement area is the manoeuvring area plus the aprons, so an aeroplane on the apron is on the movement area. The manoeuvring area excludes aprons, and air traffic means aircraft in flight or on the manoeuvring area, so the parked aeroplane is not air traffic. The first and fourth options place the apron inside the manoeuvring area. The third forgets that the apron is part of the movement area.
Reference: SERA Article 2(26); SERA Article 2(94); SERA Article 2(96)
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Two licensed pilots share a cross-country flight. The pilot designated as pilot-in-command lets the other pilot fly the second leg. Who is responsible for operating the aeroplane in accordance with the rules of the air on that leg?mcq · medium
Show answer
The pilot-in-command is responsible for operating the aircraft in accordance with the rules whether or not they are manipulating the controls. The first option moves the duty to whoever is flying. The second invents a shared duty. The fourth confuses the owner, who designates the PIC in general aviation, with the person charged with the safe conduct of the flight.
Reference: SERA.2010(a); SERA Article 2(100)
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Which of the following is counted as a psychoactive substance in the rule on the use of substances by safety-sensitive personnel?mcq · easy
Show answer
Volatile solvents are on the list: alcohol, opioids, cannabinoids, sedatives and hypnotics, cocaine, other psychostimulants, hallucinogens and volatile solvents. Caffeine and tobacco are explicitly excluded. The last option is too broad, since the definition is a defined list and the rule concerns substances that impair human performance.
Reference: SERA Article 2(104); SERA.2020
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By day, a pilot flies VFR in Class E airspace without any ATC clearance. A friend says this is a controlled flight because Class E is controlled airspace. Do you agree? Explain, and say what ATC service is designed to prevent.short · hard
Show answer
No. A controlled flight is any flight subject to an ATC clearance, not any flight in controlled airspace. A VFR flight in Class E without a clearance is not a controlled flight. The ATC service is provided to prevent collisions between aircraft and, on the manoeuvring area, between aircraft and obstructions, and to keep traffic flowing in an orderly way. Terrain is not part of that list.
Reference: SERA Article 2(59); SERA Article 2(30)
Key concepts
Written with ASD-STE100 writing principles: short sentences, one topic per sentence, active voice, one word for one meaning.
Scope of SERA
SERA applies to aircraft that operate into, within or out of the EU. It also applies to aircraft with EU nationality and registration marks, wherever they fly. Where the rules of an overflown State conflict with SERA, the local rules apply.
Rule: SERA.2001(a), (b); SERA Article 1(2)
Layers of rules in flight
An aircraft in flight must comply with the general rules and the applicable local provisions. In flight, it must also comply with either the visual flight rules (VFR) or the instrument flight rules (IFR). On the ground, the general rules and the local provisions still apply, before the flight is VFR or IFR.
Rule: SERA.2005
Pilot-in-command responsibility
The pilot-in-command (PIC) is responsible for flying the aircraft in accordance with SERA, whether or not the PIC manipulates the controls. The PIC has final authority over the aircraft while in command. The PIC can depart from the rules only when the departure is absolutely necessary in the interests of safety.
Rule: SERA.2010(a); SERA.2015
Do not: depart from the rules unless the departure is absolutely necessary for safety.
Pre-flight action
Before a flight, the PIC must become familiar with all available information for the intended operation. For a flight away from the aerodrome vicinity or all IFR flights, the PIC must make a careful study of current weather reports and forecasts. The study takes into account the fuel and energy requirements, and an alternative course of action if the flight cannot be completed as planned.
Rule: SERA.2010(b)
Manoeuvring area and movement area
The manoeuvring area is the part of an aerodrome used for take-off, landing and taxiing, without the aprons. The movement area is the manoeuvring area with the aprons added. Air traffic is all aircraft in flight or on the manoeuvring area, so an aircraft on an apron is not air traffic.
Rule: SERA Article 2(94), 2(96), 2(26)
Psychoactive substances and safety-sensitive personnel
Alcohol, opioids, cannabinoids and several other substances are psychoactive substances, but caffeine and tobacco are not. Safety-sensitive personnel do not perform their function under the influence of a psychoactive substance that impairs human performance. Safety-sensitive personnel also do not engage in any problematic use of substances.
Rule: SERA.2020
High seas and State choices
Over the high seas, the rules of ICAO Annex 2 apply without exception. A Member State publishes its own choices under SERA in its aeronautical information publication (AIP).
Rule: SERA.1001(a); SERA Article 8(2)
ATC service and controlled flight
The air traffic control (ATC) service prevents collisions between aircraft, and between aircraft and obstructions on the manoeuvring area. Any flight that is subject to an ATC clearance is a controlled flight.
Rule: SERA Article 2(30), 2(59)
Do not: expect ATC to keep you clear of terrain.
Flashcards
Print them: A6 landscape cards (PDF, front and back) · 4 cards per A4 landscape sheet (PDF, cut lines) · Key figures deck (PDF, 4 figures)
Print double-sided, flip on the short edge.
010-05-01-01Does SERA apply to an EU-registered aeroplane flying outside the EU?
Yes, unless the rules of the overflown State say otherwise. Then the local rules apply.
010-05-01-02Does SERA apply to a non-EU aeroplane flying in the EU?
Yes. It follows SERA when it operates into, within or out of the EU.
010-05-01-03What rules apply to an aircraft in flight?
The general rules and the applicable local provisions. Also either the VFR or the IFR.
010-05-01-04What rules apply on the ground, before the flight is VFR or IFR?
The general rules and the applicable local provisions.
010-05-01-05Who is responsible for flying the aircraft under SERA?
The pilot-in-command, whether or not they manipulate the controls.
010-05-01-06When can the pilot-in-command depart from SERA?
Only when the departure is absolutely necessary in the interests of safety.
010-05-01-07Who has final authority over the aircraft while in command?
The pilot-in-command.
010-05-01-08What pre-flight action does a flight away from the aerodrome vicinity need?
A careful study of current weather reports and forecasts, taking into account fuel or energy requirements and an alternative course of action. Also for all IFR flights.
010-05-01-09What is the manoeuvring area?
The part of an aerodrome for take-off, landing and taxiing. It excludes the aprons.
010-05-01-10What is the movement area?
The manoeuvring area plus the aprons.
010-05-01-11Is an aircraft on an apron air traffic?
No. Air traffic is aircraft in flight or on the manoeuvring area of an aerodrome.
010-05-01-12Which substances are psychoactive substances?
Alcohol, opioids, cannabinoids, sedatives and hypnotics, cocaine, other psychostimulants, hallucinogens and volatile solvents. Not caffeine or tobacco.
010-05-01-13Can safety-sensitive personnel work under the influence of an impairing substance?
No. Do not perform a safety-sensitive function under the influence of a psychoactive substance that impairs performance.
010-05-01-14Which rules apply over the high seas?
The rules of ICAO Annex 2, without exception.
010-05-01-15Where does a Member State publish its choices under SERA?
In its AIP.
010-05-01-16What does the ATC service prevent?
Collisions between aircraft, and between aircraft and obstructions on the manoeuvring area. Not collisions with terrain.
010-05-01-17What is a controlled flight?
Any flight that is subject to an ATC clearance.
010-05-01-18What is the pressure datum for flight levels?
1013.2 hPa.
010-05-01-19Within how many months does the competent authority inform EASA of an exemption?
Within 2 months after the exemption is approved.
010-05-01-20What is a mountainous area?
An area where terrain elevation changes by more than 900 m (3 000 ft) within 18.5 km (10.0 NM).
Sources
- Commission Implementing Regulation (EU) No 923/2012 (SERA): Article 1; Article 2; Article 3; Article 4; Article 8; Article 13; Article 71; SERA.1001; SERA.2001; SERA.2005; SERA.2010; SERA.2015; SERA.2020; GM1 SERA.2005 — via EASA Easy Access Rules for Standardised European Rules of the Air (SERA), August 2025, with the related AMC/GM.
This page is educational. It does not replace instruction at your ATO or your aircraft's POH/AFM. Rules change: check the regulation in force.