Learning hub · Air Law · Lesson 4
Aerodromes: markings, signals and the circuit
An aerodrome talks to you in paint, signs, lights and flags. Learn to read it and you can move safely on the ground and join the circuit even with a broken radio. This is the ICAO view; every national AIP adds its own detail.
About 13 minutes, plus the quiz. Part of Air Law. It builds on rules of the air and right of way.
1. Runway numbers
A runway number is the runway’s magnetic direction divided by ten, rounded to the nearest whole number. It is read from the direction in which you land or take off. A runway pointing 094° magnetic is runway 09, and a runway at 268° is 27. The two ends of one strip always differ by 18, because the directions differ by 180°: runway 09 at one end is runway 27 at the other.
Where two or three runways run side by side, letters tell them apart: L (left), C (centre) and R (right), seen from the direction of approach. Note that the number follows the magnetic direction, the same one your compass and charts use.
2. Taxiways and holding points
Taxiways have a yellow centreline, and taxiways have names, usually a letter. A sign and a marking mark the holding position where you must stop before a runway. The standard runway holding position marking is two solid and two dashed yellow lines across the taxiway. The solid lines are on the side you approach from. Do not cross them until you have a clearance or, at an aerodrome without ATC, until you have checked that the runway and the approaches are clear. When you leave the runway, you are clear only when the whole aeroplane has crossed both the dashed and the solid lines, and no clearance is needed to cross them leaving the runway.
On the runway itself you will see a threshold marking, a centreline of dashes, and the runway number. A displaced threshold is a threshold moved down the runway, and you land beyond it, though the paved area before it may be used for taxiing and take-off, and for landing from the opposite direction. Crosses on a runway or taxiway mean the surface is unfit for aircraft.
3. Windsock and signal square
The windsock shows the wind direction and gives a rough idea of its strength. The sock streams away from the direction the wind comes from, so it points the way the wind is blowing to. A limp sock means little wind; a sock standing out straight means a strong one.
Many aerodromes without ATC also have a signal area or square near the windsock. SERA Appendix 1 gives the meanings:
- A landing T (white or orange) shows the direction for landing and take-off: parallel to the shaft of the T, towards the cross arm.
- A horizontal red square with yellow diagonals means landing is prohibited, and a red square with one yellow diagonal means take special care when approaching and landing.
- A white dumb-bell means land, take off and taxi on runways and taxiways only.
- A right-hand arrow means turns before landing and after take-off are to the right.
- A double white cross means glider flying is in progress.
4. Light signals from the tower
If your radio fails, the tower can direct you with a light gun. These are the SERA signals. Acknowledge in flight by day by rocking the wings (not on base or final), and at night by flashing the landing lights, or the navigation lights, twice. On the ground by day, move the ailerons or rudder.
| Light | To an aircraft in flight | To an aircraft on the ground |
|---|---|---|
| Steady green | Cleared to land | Cleared for take-off |
| Steady red | Give way and continue circling | Stop |
| Green flashes | Return for landing | Cleared to taxi |
| Red flashes | Aerodrome unsafe, do not land | Taxi clear of landing area |
| White flashes | Land at this aerodrome and proceed to apron | Return to starting point |
A red pyrotechnic (flare) means do not land for the time being.
5. The circuit
The aerodrome traffic circuit is the standard path flown near an aerodrome so that all aircraft know where to look for each other. It has five legs and four turns: take-off and climb-out (upwind), crosswind, downwind, base and final. The names come from flying into the wind for take-off and landing. SERA.3225 says to observe other traffic, to conform with or avoid the pattern, to make all turns to the left unless otherwise indicated or instructed, and to take off and land into the wind unless safety or traffic say otherwise. A right-hand circuit exists where the aerodrome publishes it, so check the AIP.
Joining is done by the book of the aerodrome. In general you approach on a safe route that lets you look at the circuit, find the runway in use from the windsock or the radio, learn who else is in it, then fit in. Many places use an overhead join or a join on the downwind leg, but the AIP and the aerodrome entry decide this, so follow them. Circuit height is also set locally.
This lesson is the ICAO level. Markings, lighting and the exact circuit procedure differ in detail at each aerodrome. Use the AIP and the briefing of your school, and the controller’s instructions.
6. Try it yourself
Work each one out on paper first, then open the answer to compare. The numbers are invented.
You land on a runway with a magnetic heading of 163°. What is its number? What number does the other end of the strip have?
Show the answer
- Divide by ten: 163 ÷ 10 = 16.3.
- Round to the nearest whole number: 16. The runway is 16.
- The other end faces the opposite way, 163 + 180 = 343°, and 343 ÷ 10 = 34.3, so it is 34.
- Answer: 16 and 34. The numbers differ by 18.
You are on the downwind leg and your radio has failed. The tower shows you a steady red light, then later a series of green flashes. What does each mean, and how do you acknowledge?
Show the answer
- Steady red to an aircraft in flight: give way to other aircraft and continue circling.
- A series of green flashes to an aircraft in flight: return for landing. It is not yet a clearance to land, so you keep flying the circuit until a steady green.
- Acknowledge by day by rocking the wings, except on base and final.
- Answer: circle and give way, then return for landing and wait for a steady green.
Put these in the order a left-hand circuit is flown, starting from take-off: base, final, crosswind, downwind, upwind (departure).
Show the answer
- After take-off you climb straight ahead on the upwind (departure) leg.
- You turn left onto the crosswind leg, then left again onto downwind, parallel to the runway but in the opposite direction.
- You turn left onto base and left again onto final, lined up with the runway.
- Answer: upwind, crosswind, downwind, base, final. All four turns are to the left.
7. Watch
An explanation of runway markings from an air traffic channel. Aerodromes differ in detail, so treat it as the general picture.
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 walk through light signals and ground signals from a UK ground school. The signals are ICAO standard, so they match the table above, but UK local practice appears in places.
Open on YouTube if the player does not load. Not made by VectorEFB.
A UK CAA video about joining an airfield circuit in non-standard ways. Joining practice is national, so follow the Romanian AIP and your school, and take the safety idea from this video: join so that you see and are seen.
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.
Next: Mayday, Pan-Pan and lost communications. Back to the learning hub.