Signal fires and smoke

A fire laid ready in the open, lit the moment you hear an aircraft: smoke by day, flame by night.

What you need

Open ground that can be seen from the air: a shore, a bog, a clearing, a hilltop, the ice of a pond
Dry tinder, kindling and fuel, three times what you think you need
Green spruce or fir boughs, or damp moss, for smoke
Bark, boughs or a tarp to keep the laid fire dry
A lighter, matches and a fire steel

Pick the most open ground near your camp, away from overhanging trees. Smoke under a canopy spreads out and never gets seen.
Clear the spot down to rock, gravel, mineral soil or packed snow. On snow or wet ground, build on a platform of green logs.
Lay the fire ready to light: tinder, then kindling, then dry fuel, with a pile of green boughs beside it. Cover it so rain and snow stay off.
Three fires in a triangle, about 30 metres apart, is a distress signal anyone in the air will know. One good fire is better than three poor ones.
Light it the moment you hear an engine or see a boat. A laid fire should be roaring inside a minute.
By day, let it burn hot, then pile the green boughs on. A hot base under green boughs puts up a thick column of white smoke.
Against snow, dark smoke shows better than white. A little oil or a piece of rubber on the fire turns the smoke black.
At night, flame is what they see. Burn it bright and clean, not smoky.

Keep a small fire going all day beside the signal fire, so you can light it in seconds.
Gather the fuel before you need it. You will not have time once you hear the engine.
Keep water or snow close to hand to hold the fire where you want it.

Don't

Do not smother a small fire with green boughs. It goes out instead of smoking.
Do not use up your fuel on a faint engine far off. Save a blaze for when it is close or coming your way.
Do not stand downwind in the smoke, least of all from burning oil or rubber.

Danger

In a dry spell a signal fire can get away into the woods. Keep it on open rock, gravel, a shore or the ice, and never leave it.
Smoke from oil, rubber and plastic is poison. Stay upwind and use a little, not a lot.
In wind and rain smoke lies flat along the ground and is hard to see. On a still morning it stands straight up.

Three of anything means help: three fires, three whistle blasts, three shots.

A covered signal fire takes an hour to lay and can be the thing a search plane sees. See Getting found and Ground to air signals.

Updated 2026-09-29