Seeking help in the Mountains

Personal Locator Beacon (PLB) activation in remote wilderness areas has resulted in rescue in as little time as one hour, but more often several hours. PLBs transmit data such as GPS location and serial numbers directly to the Rescue Coordination Centre New Zealand (RCCNZ), who will initiate and coordinate a response. Many clubs or outdoor stores hire PLBs, and most clubs now require leaders to carry one on official trips.

Satellite Emergency Notification Devices (SEND) These devices allow a user two-way text messaging for routine communications, as well as a ‘SOS’ function to alert the RCCNZ in an emergency. Examples of devices include the Garmin InReach, SPOT tracker, ACR Bivvy Stick.

Phones. As coverage improves, more and more front-country areas have cellular signal, but mountain people shouldn’t be relying on this as a primary form of communication, or a way to ask for help in an emergency.  

New advances in technology are starting to provide satellite connectivity to phones.  This means there are ways you can set up your phone to be able to communicate when deep in the backcountry. It is beyond the scope of this article to discuss them all, and the technology is advancing rapidly.  

Because the technology is still maturing, and phones have inherent limitation (waterproofness, battery life, resistance to damage) a satellite-connected phone should be considered a supplement to other forms of communication, not a replacement.

Satellite phones were somewhat popular in the past, as were Mountain Radios, but both are rarely used these days.

Send for help. If you have no other option, leave a person with the patient, and send two people for help with a clear written description of the incident, location and other details.

Personal Locator Beacons

Personal Locator Beacons (PLBs) have been available to the public since the late 1990s. Over time they have become smaller, lighter, faster and more accurate.  Carrying a PLB is considered normal practice for most outdoor people.


The COSPAS–SARSAT program is an international search and rescue network of satellites, ground based stations and an information distribution system established in 1979. New Zealanders utilize this system with PLBs, which transmit their signal via the satellites and ground stations to Rescue Coordination Centre New Zealand (RCCNZ) in the Hutt Valley. This is funded by the New Zealand government.

How PLBs work

When a tramper, climber, hunter, sailor, or anyone else sets off a PLB, a signal is transmitted to satellites, onto ground based stations and forwarded to RCCNZ. The signal transmitted at 406MHz provides the GPS location of the unit and a unique identifier that can be matched up with the RCCNZ database. When the signal is received, RCCNZ initiates a search and rescue.

RCCNZ matches the unique identifier to its database and gets in contact with the registered emergency contact person to gather more information. The PLB also transmits a second signal on 121.5 MHz which allows helicopters and also ground teams to precisely home in on the beacon when they are getting close. This function is especially helpful in terrain where the GPS accuracy may be impacted, such as deep valleys, gorges or very thick bush.  This function can also help if the group has chosen to move location (for instance to seek better shelter). It is important to note that only a PLB has this secondary signal, which is a key reason that PLBs are more capable as an emergency communication method.

Typically, trampers see a rescue helicopter approaching within one to three hours of activation, depending on the location and favourable weather conditions. In especially remote places, or when the weather is bad, help may take much longer to arrive, so prepare accordingly.

What to look for when buying a PLB

A variety of PLBs are available in New Zealand, costing from $300 to $700. Models come in a variety of sizes, shapes, weights and battery life.  

PLBs must conform to a set of minimum standards, which include waterproofness, battery life and GPS capability.

PLBs are programmed at the point of sale with the relevant country-coding. This tells the satellites where to send the message. If you bought a beacon from an overseas shop, then any distress message has to go to that country’s rescue coordination centre, who would have to forward the information to the RCCNZ. This extra step can add a delay in the response, which is why it is important to purchase a PLB from a New Zealand-based company.

Check the expiry date, like you would check the expiry on a bottle of milk, especially if you’re buying a PLB second-hand. Typically a PLB battery expires after five to seven years. Most batteries can be replaced, but the device has to be sent to a registered service agent, and may cost 20-50% of the retail price of the PLB.

How many PLBs should a party have?

In a perfect world, each person would securely carry their own PLB (the clue is in the name: Personal Locator Beacon).     

But in practice, it depends a lot on the party and the type of a trip.  For trips where the group is highly unlikely to become separated, then a PLB or two per group may be reasonable. However, consider the scenario where the person carrying the only PLB falls into a crevasse, or off a cliff, or is swept downstream by a river and cannot set off the PLB themselves. Or if you get separated from your group on the tops, and then injure yourself. How will you get help if someone else has the only PLB?

PLB’s are small, light, and inexpensive when you consider that they can save your life.

There’s no harm in having plenty of PLB’s in a group.


After purchasing a PLB, it is a legal requirement to register it with RCCNZ at by providing your contact details and emergency contacts. It is important to keep these details up to date, and remember to re-register with your own information, if you purchase a beacon second-hand. If you hire a beacon, the hire outlet will be listed as the registered owner. Providing your party and trip details to the hire outlet allows them to pass that information on to the authorities if your beacon is activated.  Some outdoor clubs own beacons for members to use, which are registered to the club. Clubs should have an internal intentions system so the three registered people have quick and easy access to the intentions.

Practical use of PLBs

Make the PLB and your intentions part of your pre-departure checklist. At the start of your trip, tell other party members that you have the PLB, and where it is located in your pack and explain how to use it. Give your registered contact people your trip intentions. If the PLB is activated, RCCNZ can contact them and will have a much better idea of what sort of situation the rescuers may be going into.

Take a PLB even if you expect to have cell phone coverage, as cell coverage can be dubious even in areas relatively close to urban areas, especially behind ridges. Conversely, carry your cell phone also, and attempt to use it before activating a PLB. If you have to activate your PLB, do so according to instructions. Make sure you are outside (it won’t transmit through a metal hut roof). Be prepared to wait. It will take some time to muster SAR resources, and get them through prevailing weather conditions to your location.

When the battery expires, deregister the beacon with RCCNZ. It must be disposed of carefully, by taking it to your nearest police station, or couriering it to RCCNZ. This is to ensure it is not activated by accident: a number of false alerts have been tracked down to a landfill, wasting valuable search and rescue resources.


Examples of these devices are the Garmin InReach, SPOT tracker and ACR Bivvy stick.

These devices operate on commercial satellite networks, which are separate to the dedicated rescue system COSPAS-SARSAT.  Their transmitting power is often lower than a PLB, and together that means that messages are less likely to transmit in adverse conditions (such as thick bush, inside a hut, heavy rain, deep valleys etc) 

SEND generally require an ongoing, paid subscription to message, whether or not it is an emergency.

SEND often allow a user to automatically transmit ‘tracking points’ to display on a website. Solo walkers would be wise to turn on tracking, so that if an incident happens where you cannot push the emergency alert button, authorities can narrow down your last known point if you didn’t return. Scenarios could include the device is being damaged or you becoming incapacitated after a fall or being swept away in a river.

Many SEND allow two-way routine communications, which can be extremely helpful to provide updates to contact people if conditions or your plan changes. 

In an emergency, SEND have a button to press that will transmit a distress message, via the device’s company operations centre, through to the RCCNZ.  This message will include your location, and then the authorities will attempt to message you back to determine what help is required.

It is important to note that SEND do not transmit the 121.5MHz homing signal that a PLB does. This means whenever GPS accuracy is compromised (by terrain or foliage), it will be harder for searchers to pin point your location.


There are pros and cons for both devices.

A PLB is generally more capable in an emergency situation, whilst a SEND is more capable for routine communications. 

The ideal situation is each person carrying a PLB for emergencies, and a SEND (or two) within the group for routine messaging and tracking.

When should I activate a PLB/SEND?

Outdoors people are generally self-reliant and will often try self-rescue before reluctantly activating a search and rescue. There are cases of injured people stoically attempting self-rescue and suffering significant pain and distress because they do not want to incur costs to the taxpayer, or otherwise be a burden. This is incorrect thinking and ironically often costs the taxpayer more in the long term by prolonging a search or complicating your injuries when they are not treated quickly.

It does not have to be a life-threatening emergency for you to set off your PLB or activate the emergency function on your SEND. The basic rule is ‘If in doubt, get them out’. You should push the button in these situations:

Immobilised patients in significant pain with traumatic injuries clearly need rescue.

Fractured limbs such as arms or legs. If getting out under your own steam creates more pain and distress, medical evacuation is needed. If the fracture results in reduced distal perfusion (i.e. less blood circulation to for instance the fingers or toes) then this is a threat to the limb and a true medical emergency.

Consider the risk of infection of more minor injuries in the wilderness, such as eyes, especially if self-rescue will take a long time.

Many relatively minor injuries result in evacuations because of the distance from a road, the increased risk to the rest of the group, or the difficulty of terrain ahead.

Traumatic brain injuries can be a difficult call. If someone has been knocked out or concussed, even though they seem fine now, they can develop a life-threatening brain bleed over the next 24 hours. Observe them carefully for subtle changes to their consciousness such as anxiety or repetitive questioning and if these are present, get them out.

Post hypothermic/hyperthermic patients have little reserve and can deteriorate rapidly if exposed to the same conditions. Numerous people have tried to self-rescue after supposedly recovering from hypothermia, only to succumb.

Medical emergencies such as anaphylaxis, suspected heart attack, severe asthma, prolonged diarrhoea and vomiting all need rescue.

People in sustained pain not easily reduced by pain relief are in need of evacuation.  Think of the pain as an alarm system alerting you to the need for extra help. In an outdoor setting, sick people lack their normal reserves against the elements and can consequently deteriorate rapidly. Attempting self-rescue can put them and the group at risk.  Appropriate medical evacuations have occurred for conditions such as chicken pox and measles. If you think a medical or traumatic condition will warrant evacuation, set off your PLB early and prepare a helicopter landing zone (LZ).

Should the triggering of the PLB/SEND ever be delayed?

Should I wait until a suitable landing place for a helicopter is identified?

Absolutely not! If you decide that you need emergency help,  then press the button, and keep the device with the patient. It is the pilot and the rescue team’s job to choose how to perform a rescue; even if you did identify what you thought was a suitable landing place, the pilot/SAR team may still choose another place or another method (long-line/winch/stretcher carry).  Delaying the activation delay’s the response. Any team worth their salt will come and identify the location of the PLB/SEND first, then if they can’t access the injured party, they’ll find the next best way. Trying to move that person that distance could have aggravated the injury to the point of incurring long term or permanent damage.  Separating the PLB/SEND from the injured person only creates difficulty to find the person! It is extremely difficult to see people from a helicopter in dense bush. Aids such as a distress beacon, radio, emergency flare, or smoky fire greatly improve your chances of being spotted sooner. 

What if it’s night time, should I wait until the morning?

PLB’s are binary, there is only “off” and “activated”.  Even if your reason for activation is more in the category of “not life threatening, but still requiring evacuation due to our location” there’s no way for rescuers to know what the situation is. So their only choice is to respond to an activation as though there is serious and imminent danger to life or limb. That can mean putting themselves into considerable danger to get to a person in difficult conditions. If you have a stable and comfortable patient, who along with the rest of the group is warm and dry in a hut and there’s a storm raging through the night then, by definition, there is no imminent danger. In this instance you could consider waiting until the morning.  For example, a patient who was hypothermic, but is now re-warmed and well cared for in the hut, or a relatively minor injury like a broken ankle which has been given good first aid and sufficient pain medication: it isn’t going to change the outcome by being rescued 12 hours earlier! But if you are not completely sure of the patient’s stability, their situation deteriorates, or you have any doubt that waiting is the right thing to do, then don’t hesitate activating the PLB.

SEND allow two-way communication after activating the emergency function.  A conversation with RCCNZ may allow a tailored response, in the best interests of the group wanting help as well as the rescuers. So it is more reasonable to activate the emergency function on a SEND as soon as you know that help will be required.

What can you do to assist rescue?

No more accidents! Make yourself, your group and the patient safe.

Leadership – take control. Cool analysis and implementation of a plan are vital.

Good, clear communication is crucial.

Attend to the physical (food, fluid, warmth and rest) and emotional well-being of everyone.

As memory often becomes unreliable in times of stress, write everything down, including: location – map series, grid reference/GPS coordinates and physical description; accident details – what happened; personal details of the patient including next-of-kin contacts, medical conditions, allergies, medications; weather and terrain conditions; patient details including injuries, illness, treatments and observations. Give these written observations to your rescuers.

What do we need to prepare for a helicopter rescue?

The helicopter needs to find you, which can be the most difficult part of the operation. Accurate location information is vital. In daylight, make yourself visible with smoke, flares, reflectors, or by shaking trees. At night, if the helicopter has night vision capability they will see lights from a long way off: people have been rescued at night from the light of their cell phone screen.

The helicopter crew will select their own landing site if they need one.  The crew will be looking for something about tennis court size, relatively flat, free of obstacles (such as wires) on the approach, and free of loose objects. After circling the site, a helicopter will generally land into the wind. 

If there is a suitable place nearby, and it is safe to do so, position someone at the far upwind boundary of the landing site with their back to the wind and arms horizontal from their sides. Have only the minimum number of people absolutely necessary at the site.

Even without a landing site, the helicopter can still rescue you. Numerous winch rescues occur every year in difficult terrain or dense heavy bush. If you can, make sure the patient is completely packaged, with all their personal gear and a written handover for the rescue crew. The helicopter may allow additional passengers, so prepare for this.

For operations after dark most dedicated rescue helicopters now have night vision capability. This is very sensitive technology: lights shone at the helicopter from the ground may blind the pilot. Once the pilot has spotted you and is obviously making an approach to land, keep torches shining downwards as they approach.

Safety around helicopters

In a rescue situation, the helicopter will almost always have a crew member who will take charge of the situation, and manage the movement of people in and out of the machine. 

The best advice is to stay where you are when the helicopter is approaching, and wait for instructions from a crew member. 

If there isn’t a crew member or they cannot come to give you assistance for any reason, these general guidelines will help keep you safe.

Approach from the 10 o’clock or the 2 o’clock position to avoid the main rotor blade.

Never go near the rear of the helicopter (to avoid the tail rotor). Always obtain approval (thumbs up or very deliberate nod of head) from the pilot or crew before approaching the helicopter.

If the helicopter has landed on a hillside slope, the rotor on the uphill side may be very close to ground level. Always approach from below the level of the helicopter after getting pilot/crew approval.

Rotor downwash is very powerful. Secure loose articles of clothing including hats, caps or other equipment before approaching the helicopter. If an item blows away, don’t chase it.

If you are carrying long pieces of equipment such as skis, carry them horizontally, below the waist, to prevent contact with the main rotor.

If rotor wash or dust impairs your vision, crouch down and stay where you are until you can see again.

Take your time. The noise, wind and stress of the incident create a sense of urgency which can cause undue haste.

Think before you act.

This article was first published in the August 2016 issue of FMC’s Backcountry magazine. It was reviewed and updated in 2019 and again in 2023 by Daniel Clearwater.

To subscribe to the print version of Backcountry Magazine, please visit The Backcountry Accidents Column, in one form or another, has been a feature of FMC publications since 1938. Read Shaun Barnett’s article on the history of the column to understand the thinking behind this highly regarded series of articles.