Signalling to helicopters (Y/N) and behaviour during landing

From the air, words are inaudible and details are hard to see. What you can see well from above are large, simple shapes. That is why the signals are chosen so that the whole body forms a clear figure: a Y with both arms up, an N with one arm up and one down.

Standing still in the posture is better than waving. Waving blurs the shape, and the crew cannot be sure what is meant. Hold the posture as long as the helicopter is facing you or circling overhead. If possible, stand against a calm, high-contrast background – for example dark clothing against snow or bright clothing against forest.

The crew does not only read your signal but the whole situation: how many people are there, is someone lying on the ground, what is the terrain like? Your signal is important information, but the crew makes the decision.

A helicopter flies over you and then turns back as if it were looking for something. It may be looking for you, or for someone else. If you need help, show the Y clearly. If you do not, show the N – that helps the crew continue searching sooner.

Many people wave at helicopters out of joy or as a greeting. That is understandable, but it can be misread, because two raised arms resemble the Y signal. If you are out walking and everything is fine, just watch, or show the N if the helicopter is obviously reacting to you.

The rotors are deadly. The small tail rotor at the back of the helicopter in particular is almost invisible when it is turning. Never approach from behind. On a slope the main rotor can be much closer to the ground on the uphill side than on the downhill side – so never approach from uphill. Only go when the crew invites you, crouched and from the front, where the pilot can see you.

The rotor downwash is very strong. It whirls up snow, sand, grit and branches and can lift loose objects – jackets, hats, emergency blankets, tarps. If something like that is drawn into the rotors, it endangers the aircraft and everyone on board. Gather up loose things in good time or weigh them down, protect your eyes and face and find a secure stance.

Unless the crew signals otherwise, it makes sense to kneel with your back to the wind as the helicopter comes in to land. That keeps you stable and shields you from flying debris. The crew's instructions always take priority over anything you have learned.

The Y/N signals are a widespread convention in alpine air rescue in Europe and are taught by alpine clubs and mountain rescue services. Other parts of the world may use different body signals. If you travel far, find out beforehand. The general rule everywhere: calm, large and unambiguous is better than frantic.

The signals do not replace an emergency call. If you have signal, call the local emergency number (112 in the EU); then the dispatch centre already knows where and why help is needed. The body signals help mainly when a helicopter is already in the area. This entry is not a guide to winch rescue or to marshalling a landing – that is a job for trained people.