Light gun signals: what every colour means
When the radio fails, the tower talks to you with a light gun. The same light means different things in the air and on the ground, and that is exactly what the exam asks. Below is the table from SERA Appendix 1, then the tricks that make it stick.
The table
| Light from the tower | Aircraft in flight | Aircraft on the ground |
|---|---|---|
| Steady green | Cleared to land | Cleared for take-off |
| Steady red | Give way to other aircraft and continue circling | Stop |
| Green flashes | Return for landing* | Cleared to taxi |
| Red flashes | Aerodrome unsafe, do not land | Taxi clear of landing area in use |
| White flashes | Land at this aerodrome and proceed to apron* | Return to starting point on the aerodrome |
| Red pyrotechnic | Notwithstanding any previous instructions, do not land for the time being | – |
* This is not a clearance. Clearance to land and to taxi will be given in due course. Source: SERA Appendix 1 (Standardised European Rules of the Air), based on ICAO Annex 2.
Four ways to remember it
- Colour is intent. Green means go, red means stop or not now, white means come home – to the apron in the air, to the starting point on the ground.
- Steady lights say go or hold, flashing lights redirect you. Steady green: go (land, take off). Steady red: hold – stop on the ground, give way and keep circling in the air. Flashes tell you where to go or what to stay away from.
- Green is always forward, red is always away. Green flashes: back towards a landing, or onwards to taxi. Red flashes: away from the runway – do not land, or get clear of it.
- A red flare beats everything. It cancels every earlier instruction, even a clearance you already have.
How to acknowledge a light signal
| By day | By night | |
|---|---|---|
| In flight | Rock the wings (not on base leg or final approach) | Flash the landing lights, or switch the navigation lights on and off, twice |
| On the ground | Move the ailerons or rudder | Flash the landing or navigation lights twice |
Where students lose marks
- Steady green on the ground is take-off, not taxi. Taxi is the flashing green.
- Flashing green in the air is not a landing clearance. It tells you to return for a landing; the clearance follows.
- Steady red in the air does not close the aerodrome. You give way and keep circling. The aerodrome is unsafe only when the red flashes.
- White flashes exist in both columns. Apron in the air, starting point on the ground.
Light signals sit in Air Law (010) next to radio failure and the signals for aerodromes. Check the current SERA text before an exam: this page is a study aid, not the regulation.
Quick answers
What does a flashing green light from the tower mean?
To an aircraft in flight: return for landing. To an aircraft on the ground: cleared to taxi. Neither is a landing clearance – that follows in due course.
What does a steady red light mean?
In flight: give way to other aircraft and continue circling. On the ground: stop.
What does a flashing white light mean?
In flight: land at this aerodrome and proceed to the apron. On the ground: return to the starting point on the aerodrome.
How do you acknowledge a light signal?
In flight by day: rock the wings (not on base or final). In flight by night: flash the landing lights or the navigation lights on and off twice. On the ground by day: move the ailerons or rudder. On the ground by night: flash the landing or navigation lights twice.
Make it stick
Fly the Light Signals drill: every item is a streak you have to land.