Photo Crusier, CC BY-SA 3.0

Ground to air signals

Big shapes on open ground that a plane or helicopter can read, and the few codes worth knowing.

What you need

An open place a pilot can see: a bog, a clearing, a shoreline, a frozen pond
Material that stands out: spruce boughs on snow, rocks or logs on moss, bright gear on anything
Something to make smoke: green boughs ready beside a fire
Your orange gear, space blanket or tarp

Pick the most open ground near you. Searchers fly over clearings, shorelines and ridges.
Make each shape big, at least three metres long, with lines as wide as you can manage.
Use contrast: dark boughs on snow, pale rocks on dark moss, a trench stamped in snow that throws a shadow.
Lay one clear signal. V means we need help. X means we need medical help. An arrow shows the way you went.
Three of anything reads as distress: three fires, three piles, three whistle blasts.
Keep a fire laid and ready with green boughs beside it. Light it and smother it with the boughs when you hear an aircraft.
When the aircraft sees you it will usually rock its wings or circle. Stay where you are.

Build the signal close to where you are sheltering so you are there when help comes.
Leave the arrow if you have to move, pointing the way you went.
Wave both arms over your head if you need help. One arm means all is well.

Don't

Danger

Fresh snow buries a snow signal overnight. Stamp it out again every morning.
A signal fire in dry weather can start a forest fire. Clear to bare ground and keep water handy.
Waving casually at a passing aircraft can look like all is well. Use the two arm signal.

The letters come from the international emergency code that pilots are taught. You do not need them all. V, X and an arrow cover almost everything.

If you can, write SOS as well. Every pilot knows it.

Updated 2026-09-22