Bushwalking Rescue: Emergency Evacuation by Helicopter

Have you ever needed a helicopter rescue? Ever raised the alarm using your (personal locator beacon) PLB or marine EPIRB? What can you do to make the landing or winching site safer? How can you attract attention and give signals to a circling aircraft? What information do you need to provide?

Well I’m fortunate and have never needed a helicopter rescue, neither has anyone in any of my groups. Nor have I ever had to raise the alarm using my PLB (personal locator beacon) or EPIRB, but I have walked in lots of areas in Tasmania where this is a regular occurrence, either due to poor weather, bushfire or injury.

On occasions, I have seen a helicopter circling and wondered whether someone is in trouble. On one occasion I was approached on a track by Parks and Wildlife staff who had been in radio contact with a rescue helicopter which had been circling and were trying to locate a person who had set off an EPIRB (emergency beacon) and then left the spot, tuning off their beacon when they left.

On most of my walks into isolated areas I have taken an EPIRB ( no longer licensed), now replaced by a PLB. Walking in the Gammon Ranges and further north I have taken a VHF radio for communication with nearby homesteads. Along the south coast and south west coast of Tasmania,  I have taken a marine radio for communication with passing fishing boats. Of course I always have my signalling mirror and mobile phone with me!

Alerting Rescue Services

Modern technology has provided us with several devices

NB Tasmanian Parks and Wildlife has PLBs for hire

    Alert Detection

    Radio distress beacons operate on 406 MHz with a 121.5 MHz transmission feature being used for final stage homing.
    NOTE: After 1 Feb 2010, old analogue EPIRBs and PLBs operating on 121.5 MHz are no longer licenced for use.
    The technology of distress beacons is so advanced that the location of the boat, aircraft or individual in distress can be calculated to a search area of as little as 110m with a digital 406 MHz beacon, if encoded with GPS.
    A digital 406 MHz beacon can relay much more information than simply the distress location.  When registered properly with AMSA, 406 MHz distress beacon can provide the RCC Australia with information such as the registration details of the aircraft, vessel or vehicle as well as emergency contact names and contact numbers.   This may allow further information to be gathered relating to the type of craft, survival gear carried and the number of people on board etc.  REGISTRATION IS FREE.
    After defining the search area, aircraft or other rescue craft rely on homing equipment to locate the beacon’s exact position.
    It is important that once a beacon is switched on in a distress situation you should not switch it off until rescue has been affected or you are advised to by the rescue authority. ”  Australian Marine Safety Authority

      Traditional methods include

      • lighting signal fires: three fires in a triangle for an emergency.  Have green vegetation handy to create smoke.
      • signaling with a mirror:  lightweight signaling mirrors with a hole in the middle to assist location are cheap
      • laying out markers and recognised symbols

      Ground to Air Signals

      • V require assistance
      • X require medical assistance
      • SOS: repetition of 3 signals, separated by a minute

      The following universal signals  are for strip signals, recommended to be built from rocks or tree branches or dug in the ground and are designed to be seen from the air. Make your signal big ( 6 -10m  by 1 m, with at least 3 m between symbols) so that it can be seen from a distance, and select a highly visible location.

      Wilderness Survival Forum

      N – No, Negative
      Y,  or A – Yes, Affirmative
      A square – require map and compass

      Preparing the landing area

      • Chopper can only descend vertically 15 metres
      • Select landing spot with clear approach and exit into the wind, clear 25m diam landing spot with a further 5m no more than 60 cm high, no more than 10% slope.
      • Mark landing area with a large H
      • Streamers or smoke to mark wind direction
      • Clear the landing spot of loose debris. Eye protection should be worn.
      • Approach helicopter from front & lower side on slope only when signaled.

      Abandoning Camp

      If you have to abandon camp, leave clear direction markers to show where you have gone and continue to mark the track, so you know if you have doubled back.


      Creative Commons License
      This article by Bush Walker is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.


      3 thoughts on “Bushwalking Rescue: Emergency Evacuation by Helicopter”

      1. A fascinating blog post thank you for sharing. At Heli Operations we work closely with the world's largest helicopter operators, providing crews, equipment, training and support to specialist operations in the maritime environment and the challenging Search and Rescue role. We were very interested to read this article and wish you and your readers all the very best.


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