If you find yourself in the great outdoors and in need of some assistance you should be aware of the signal codes that are generally recognized by those who may be searching for you. Hopefully, you will never need this information, but you should still be prepared.
Before you leave you should probably tell at least one person where you are going along with an idea of your timeline, and how long you expect to be away. If nobody has heard from you for some time and the alarm is raised there is a good chance that an airplane or helicopter will be deployed to search for you.
The following are the ground to air signals you can use to communicate simple messages to those searching for you from above and will give them an idea of what your needs are or what they may find on landing.
V This is a signal requesting general assistance.
X This ups the urgency somewhat in the case of medical assistance being required.
N Negative or NO. A reply if the rescuers are able to ask a question of you.
Y Affirmative or YES in the same way as the above.
-> An arrow pointing towards the place where the help is needed.
In any situation, a group of three signals of any kind confirms distress. For example, three Xs means medical attention is urgently needed. Arrows also are very important to help rescuers find your location.
You will need to find an open area close to where the assistance is needed, where you can “build” your signals. The highest, flattest area is the best place to choose. When building your signals remember that they need to be seen clearly from the rescue aircraft, so bigger is better.
Use rocks and branches and any other materials at hand. Do your best to ensure a good contrast between the materials used and the surface you are putting them on – for example, dark rocks on snow or green leaves against bare sand. You could also have a back-up which could be a mirror by which you can try to signal the aircraft when you see it, or you could try smoke signals using wet wood on a fire. Remember, the idea is to be seen.