How do pilots find an aerodrome at night?
A beacon on or beside the aerodrome flashes white alternating with a colour, in every direction, so the field can be picked out from far away.
An aerodrome beacon is a light that shows the pilot where the aerodrome is. It is provided where it is operationally necessary, for example at an aerodrome used at night that is hard to find among surrounding lights. It shows in all directions and flashes white alternating with a coloured flash: green for a land aerodrome and yellow for a water aerodrome. Some aerodromes use white flashes only.
The total flash rate is 20 to 30 flashes per minute, white and coloured counted together, and the white flash has an effective intensity of at least 2,000 cd. The light starts at 1° or less above the horizon and spreads upward far enough to guide pilots at the limit of their use of it. It is placed on or next to the aerodrome, in an area of low background lighting, and positioned so it does not dazzle pilots on final approach. A separate identification beacon flashing a Morse code group is used only where the aerodrome needs to be told apart from others.
Frequently Asked Questions
Q1What is an aerodrome beacon?
A light that shows in all directions and flashes white alternating with a colour, so a pilot can find the aerodrome from the air at night or in poor visibility. It is a location marker for the whole aerodrome, not a guide to a runway.
Q2What colour is an aerodrome beacon?
A land aerodrome beacon flashes white alternating with green. A water aerodrome beacon flashes white alternating with yellow. Some aerodromes use white flashes only. The colour tells the pilot what kind of aerodrome it is.
Q3How fast does an aerodrome beacon flash?
ICAO sets the total flash rate at 20 to 30 flashes per minute, counting white and coloured flashes together. A rotating beacon with a white and a coloured beam on opposite sides gives two flashes per turn, so one turn every 5 seconds gives 24 per minute. US practice (FAA) asks for 24 to 30 per minute, so a rate in that band satisfies both.
Q4Where is the aerodrome beacon placed?
On or next to the aerodrome, in an area of low background lighting, and positioned so it does not dazzle pilots on final approach. It is often mounted on a tower or on top of a building so it can be seen from far away.
Q5What is the difference between an aerodrome beacon and an identification beacon?
The aerodrome beacon shows where an aerodrome is. An identification beacon flashes a Morse code group so the pilot can tell which aerodrome it is, and it is used where the aerodrome cannot be identified by other means. Each is a separate light with its own requirements.
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