What type of airport is it?

The rotating beacon

At night, the airport's rotating beacon is often the first part of the airport a pilot sees. The colors of the flashes, and the pattern they come in, tell you what kind of airport it is.

The color codes

• Civilian land airport -- White and green, alternating. One white flash, then one green.
• Civilian water airport -- White and yellow, alternating.
• Heliport -- Green, yellow and white.
• Military airport -- White and green, like a civilian land airport, but with two quick white flashes between each green.

Count the white flashes

A civilian land airport and a military airport use the same two colors, so the colors alone won't separate them. Count the white flashes between the greens. One white flash is a civilian land airport. Two quick white flashes is a military airport. The difference matters, because a civilian airplane can't land at a military airport without permission, except in an emergency.