LAW 008

Aerodromes

What an aerodrome is

A defined area on land or water, including any buildings, installations and equipment, intended to be used wholly or in part for the arrival, departure and surface movement of aircraft.

TypeControlled

Air traffic control service is provided to aerodrome traffic. Taught in LAW 004.

TypeUncontrolled

No air traffic control service.

The main parts

Runway

Taxiway

Apron

An aerodrome is also divided into two sides: airside and landside.

Aerodrome reference point (ARP).The designated geographical location of an aerodrome. It is measured and reported to the AIS in degrees, minutes and seconds.

The areas, one inside the next

Three names for three parts of the same ground. Each takes in the one before it.

Everything used for take-off, landing and taxiing is movement area. Take the apron away and what is left is manoeuvring area, taxiways included. Keep only the runway and it is landing area.

Movement areaThe part of an aerodrome used for take-off, landing and taxiing: the manoeuvring area and the apron.

Manoeuvring areaThe part used for take-off, landing and taxiing, excluding the apron.

Landing areaThe part of the movement area intended for landing or take-off.

Runway, taxiway, apron

The three main parts, defined.

Runway (RWY)A defined rectangular area on a land aerodrome, prepared for the landing and take-off of aircraft.

Taxiway (TWY)A defined path on a land aerodrome for the taxiing of aircraft, linking one part of the aerodrome with another: the hangar, the terminal, the runway.

ApronA defined area on a land aerodrome, intended to accommodate aircraft for loading or unloading passengers, mail or cargo, fuelling, parking or maintenance.

Types of runway

Instrument runwayPrecision approach, or non-precision approach.

Non-instrument runway

Taxiways are named with letters: A, B, C, with an optional number after the letter, such as B2.

Round the runway

The areas built round a runway, and the threshold that is not always at its end.

The strip holds the runway and the stopway. The clearway starts at the end of the take-off run available, here the end of the runway, and the RESA starts where the strip ends.

Runway stripA defined area including the runway and the stopway, if there is one. It is there to reduce the risk of damage to an aircraft running off the runway, and to protect aircraft flying over it during take-off or landing. It extends sideways to a specified distance from the runway centre line.

ShoulderAn area next to the edge of a pavement, prepared as a transition between the pavement and the adjacent surface. Along a runway the pavement is the runway itself, so the shoulders run along both its edges, between the runway and the rest of the strip.

Runway turn padA defined area next to a runway for completing a 180-degree turn on the runway.

Displaced thresholdA threshold not located at the extremity of the runway. The runway before it still counts for take-off in either direction, and for landing from the other end. It does not count for landing towards this threshold: only that LDA is shortened.

StopwayA defined rectangular area on the ground at the end of the take-off run available, where an aircraft can be stopped in the case of an abandoned take-off.

ClearwayA defined rectangular area on the ground or water, over which an aeroplane may make a portion of its initial climb to a specified height.

Runway end safety area (RESA)An area symmetrical about the extended runway centre line and next to the end of the strip, mainly to reduce the risk of damage to an aeroplane that undershoots or overruns the runway.

Declared distances

Four lengths an aerodrome declares for each runway direction. Each starts somewhere different, which is the thing to learn.

LDA starts at the threshold. The other three start at the beginning of the runway: ASDA runs on over the stopway, and TODA over the clearway.

TORATake-off run available

The length of runway declared available and suitable for the ground run of an aeroplane taking off.

TODATake-off distance available

The take-off run available, plus the clearway if there is one.

ASDAAccelerate-stop distance available

The take-off run available, plus the stopway if there is one.

LDALanding distance available

The length of runway declared available and suitable for the ground run of an aeroplane landing.

Aerodrome reference code (ARC)

Used for aerodrome planning: it describes the aeroplanes a facility is built for. Two elements, written together with the number first, such as 4C.

Element 1: code number
Code	Aeroplane reference field length
1	Less than 800 m
2	800 m up to but not including 1 200 m
3	1 200 m up to but not including 1 800 m
4	1 800 m and over

Element 2: code letter
Code	Wingspan
A	Up to but not including 15 m
B	15 m up to but not including 24 m
C	24 m up to but not including 36 m
D	36 m up to but not including 52 m
E	52 m up to but not including 65 m
F	65 m up to but not including 80 m

The number comes from the longest aeroplane reference field length among the aeroplanes the runway is meant for, the letter from the greatest wingspan. The field length is the aeroplane’s, not the runway’s: Annex 14 uses it only to pick the code number, not to set how long a runway is built.

Pavement strength, and services

PCNPavement Classification Number

A number expressing the bearing strength of a pavement for unrestricted operations. It is how ICAO has pavement strength reported.

ACNAircraft Classification Number

A number expressing the relative effect of an aircraft on a pavement, for a specified standard subgrade category.

Replaced in 2024. Since 28 November 2024 ICAO uses the ACR-PCR method instead: ACR, Aircraft Classification Rating, and PCR, Pavement Classification Rating.

Services at the aerodrome

Handling

Rescue and firefighting

Runway designators

The number painted on the end of a runway, and the letter that goes with it when there is more than one.

The designatorTwo digits: the whole number nearest one-tenth of the runway’s magnetic bearing, seen from the direction of approach. A single digit gets a zero in front. Annex 14 words it as “the whole number nearest the one-tenth of the magnetic North”, which means the same.

For example A runway on 253° magnetic is 25. The other end, on 073°, is 07. Together they are runway 25-07, as on the sign further down.

Parallel runwaysA letter is added: L, C or R, for left, centre and right.

Four or more parallel runwaysOne set of adjacent runways takes the nearest one-tenth of the magnetic bearing, the other set the next nearest one-tenth.

The letters, left to right

2runways

3runways

LCR

4runways

LRLR

5runways

LCRLR

LRLCR

6runways

LCRLCR

06L06R07L07R

Seen from the direction of approach. A gap is where the letters start again: the set after it takes the next designator number, such as 06L and 06R, then 07L and 07R.

Markings and signs

Paint on the ground, and signs beside it.

Runway markings

Runway designator
Threshold
Runway centre line
Aiming point
Runway side stripe, along the edge
Touchdown zone

Runway markingsWhite.

Taxiway markingsYellow.

Signs

Mandatory instruction signs

White on red. An aircraft or vehicle does not go past one unless the aerodrome control tower has authorised it.

A25-07 Location and runway designation

You are on taxiway A, at runway 25-07.

B2 Runway-holding position

The taxiway designation and a number: taxiway B, holding position 2.

Information signs

Black on yellow. A location sign is yellow on black.

AC Location and direction

You are on taxiway A. Taxiway C leads off to the left and to the right.

C Direction

Taxiway C is ahead and to the left.

Runway lights, and slope indicators

Four kinds of light on the runway itself, then three ways of showing a pilot whether the approach is too high or too low.

Threshold lightsAcross the threshold, where the part usable for landing begins, showing green towards the approach.

Green

Runway end lightsAcross the far end of the runway, showing red in the direction of the runway.

Red

Runway edge lightsAlong both edges of the runway. Red before a displaced threshold, and the last 600 m may show yellow.

White

Runway centreline lightsAlong the centre line. Red and white alternating from 900 m before the end, red for the last 300 m.

White, then red

Visual approach slope indicators

PAPIPrecision Approach Path Indicator

VASIVisual Approach Slope Indicator

PLASIPulsating Light Approach Slope Indicator

Position	PAPI	VASI	PLASI
Too high			Pulsing
Slightly high			Pulsing
On glide slope			Steady
Slightly low			Steady
Too low			Pulsing

Seen from the approach. The PAPI stands on the left of the runway, so the red lights are the ones nearest the runway: as the approach gets lower, the units turn red from the runway side outwards. The VASI shows three states, not five: high and slightly high look the same, and so do low and slightly low.

In the AIP

Part 3

Aerodromes

AD 0 to AD 3. Aerodromes are in Part 3 of the AIP, AD, from AD 0, its table of contents, to AD 3, heliports. The whole book is in LAW 006.

AD 0Table of contents
AD 1Aerodromes: introduction
AD 2Aerodromes
AD 3Heliports

Heliport

An aerodrome, or a defined area on a structure, intended to be used wholly or in part for the arrival, departure and surface movement of helicopters.

Reading material

Aviation Law

LAW 008 Aerodromes PowerPoint / PDF

Regulation (EU) 2017/373 (Rules for ATM-ANS), ATS.TR.260 Reading list, free

eLearning Aerodromes Reading list, course material

International Civil Aviation Organization, Procedures for Air Navigation Services: Air Traffic Management, Doc 4444, 16th edition, 2016 Reference, part free

International Civil Aviation Organization, Annex 14, Aerodromes, Volume I, Aerodrome Design and Operations, 8th edition, July 2018 Reference, part free

European Union Aviation Safety Agency, Easy Access Rules for Aerodromes (Regulation (EU) No 139/2014), December 2024 Reference, free

ICAO Annex 14, Aerodromes, Volume II: Heliports ICAO document