How to make ground-to-air signals

Using symbols to signal a plane for help is essential if you’re stranded, Lost-style, on an island somewhere. But it’s also a handy skill to have even if plane pick-up and drop-off is an expected part of your backcountry trip, as a way to communicate a vital message to your pilot. You can use branches or rocks to construct symbols, but brightly coloured gear, or anything that contrasts well with the ground, will work better. Make your symbols at least three feet wide and eight to 10 feet long.

A straight line: Require a doctor

Two parallel lines: Require medical supplies

An "X" shape: Unable to proceed

An "F" shape: Require food/water

A "K" shape, which acts as an arrow: Indicates direction to proceed

An arrow with a tail: I'm proceeding in this direction

A triangle: Probably safe to land here

Two "L" shapes side by side: All is well