Bushwalk Australia

In a recent incident, a PLB was set off about 10am in a remote area (Wollemi NP) after a fall. AMSA called the contact and was given detailed info about how many people, where they were, experience level, etc.

The people in the bush saw nothing until about 2:30pm, 4.5 hours later, when a light plane began circling over them. By this stage they were wondering whether the PLB was faulty.

Just wondering if there are any guidelines for when to take further action if there seems to have been no response? This group had several PLBs and it would have been possible to set off another one, but how long should they wait before doing this?

(Not criticising rescue services here. Just trying to work out what to do in the event that the PLB may have failed.)

It has been some time since i researched this but the nuts of it are : there may be appx two dozen satellites orbiting the planet for the purpose of catching PLB signals. It may take a couple of hours before the signal is received and it is likely that two satellites will have to get the signal before any significant action is taken. That information is transferred to one of three locations around Australia and they in turn contact any aircraft or vessel in the your vicinity to investigate.
It may well take a lot longer then for them to pinpoint you and organise a rescue.

An incident i was involved in a few years ago i was able to make phone contact and the PLB was not set off. However, the helicopter that was trying to see us through a thick canopy of rainforest asked my phone contact to get me to set the PLB off. The problem was they only had minutes left to stay on station due to fuel shortage. I set the PLB off and they then saw us through the canopy. I really don't know if they just managed to see some colour in time and spot us or if the PLB made any difference.

Aardvark wrote:It may take a couple of hours before the signal is received and it is likely that two satellites will have to get the signal before any significant action is taken.

The contact was phoned about 10:30am, half an hour after the PLB was set off.

But nevertheless, what is a reasonable time to wait for a response before trying something else? You cannot just sit there forever with a sick or seriously injured person.....

davidmorr wrote:

Aardvark wrote:It may take a couple of hours before the signal is received and it is likely that two satellites will have to get the signal before any significant action is taken.

The contact was phoned about 10:30am, half an hour after the PLB was set off.

But nevertheless, what is a reasonable time to wait for a response before trying something else? You cannot just sit there forever with a sick or seriously injured person.....

When I asked PLB response time was upto 3 hours... time from activation to someone coming out to you - that can be an overflight by aircraft.

Remote area first aid training is for patient care of days... Seniors first aid training is for the first 30 mins, this is for an abo response with cell phone coverage. If your not in cell phone coverage or not in vehicle access then you need more than Senior First Aid training.

30 mins looks like a long time for PLB activation to phone contact for checking. No time zones involved?

Only one satellite is needed for activation but a location is required and one satellite does not give you that with any accuracy unless the PLB is GPS equipped.
------------------------
PLBs have a test button for a reason - test it before you use it!

PLBs have 2 signals - both get transmitted together;
One for the satellite 406MHz
One for ground location 121.5 MHz - search planes/helicopters are able to receive it and zero in on it. Commercial aircraft also receive these and do contact and report their reception and give an approximate location from their flightpath based on signal strenth.

If you are in a canyon there is limited view of the sky - this may limit the satellites reception and lead to a delay.

Warin wrote:Remote area first aid training is for patient care of days... Seniors first aid training is for the first 30 mins, this is for an abo response with cell phone coverage. If your not in cell phone coverage or not in vehicle access then you need more than Senior First Aid training.

Yes, all remote area qualified. But in an incident yesterday the issue was heat injury where the methods of managing it (keep cool, plenty of fluids, etc) were not available. We did not have to use a PLB fortunately, but in that case time is a factor.

30 mins looks like a long time for PLB activation to phone contact for checking. No time zones involved?

No, all in NSW.

Only one satellite is needed for activation but a location is required and one satellite does not give you that with any accuracy unless the PLB is GPS equipped.

PLB had GPS. Cannot imagine why you would get one without GPS.

PLBs have a test button for a reason - test it before you use it!

That does not prove it is fully working. It is just an indication that at least some of it is. (Years of working in IT where diagnostics only test the known types of problems. Cannot help with unknown types.)

Warin wrote:Only one satellite is needed for activation but a location is required and one satellite does not give you that with any accuracy unless the PLB is GPS equipped.

However, due to the number of false applications (that is PLB's set off by accident or otherwise), authorities might wait for two satellites to pick it up before acting.

"a PLB was set off about 10am in a remote area (Wollemi NP) after a fall. AMSA called the contact..." If they had phone reception, why not call 000 first?

Errr ... The contact is not the person who set off the plb but rather the person with details of the party and their route etc who remains back in civilisation.

There are only a small number of rescue helicopters available, and the further you are from one of their bases the longer it will take. If other rescues are taking place, or urgent medical transfers are required between hospitals (in NSW the same choppers get used for some of these) then it can be quite some time before they get overhead.
In most bushwalking settings, I would be surprised if you were located by a rescue chopper in less than 3 or 4 hours from setting off the PLB.
If you add in the challenges of weather (low cloud, strong winds, etc) you should always be planning / ready to spend a night in the bush following an emergency activation.
In a number of incidents I am aware of there were paramedics / doctors lowered in to stabilise the patient, with the extraction then not taking place until the next morning. The fuel situation is quite limiting, so even in ideal circumstances the rescue party will be lowered in, the chopper will fly away to refuel, then an extraction will occur on its return.
Do be aware that the more sky you can see, the quicker your PLB will be able to reach a satellite, so if you're in a narrow gorge or canyon, move up or downstream to an area with more sky visible, or try to get to higher ground. I know of a rescue in a canyon where the first PLB was set off where the incident occurred, then a second one was activated a short way up a ridge. It took an hour or more for the canyon PLB to be picked up, but the ridge one was picked up almost instantly.

It's a length of string question isn't it? If you set off a PLB you wait until help arrives, or at least that is how I understand the instructions that came with mine, that is you do not move around but stay close to where the first signal was sent from. I now do own one for my beloveds peace of mind but I can't ever see myself setting it off.

Aardvark wrote:It has been some time since i researched this but the nuts of it are : there may be appx two dozen satellites orbiting the planet for the purpose of catching PLB signals. It may take a couple of hours before the signal is received and it is likely that two satellites will have to get the signal before any significant action is taken. That information is transferred to one of three locations around Australia and they in turn contact any aircraft or vessel in the your vicinity to investigate.
It may well take a lot longer then for them to pinpoint you and organise a rescue.

An incident i was involved in a few years ago i was able to make phone contact and the PLB was not set off. However, the helicopter that was trying to see us through a thick canopy of rainforest asked my phone contact to get me to set the PLB off. The problem was they only had minutes left to stay on station due to fuel shortage. I set the PLB off and they then saw us through the canopy. I really don't know if they just managed to see some colour in time and spot us or if the PLB made any difference.

PLB's can also transmit on a frequency used for local direction finding equipment that can be fitted to SAR helicopters and ground based SAR teams, once they get close to help pinpoint the location... although it can be thrown out by large angular rock faces bouncing the signal around.

FatCanyoner wrote:Do be aware that the more sky you can see, the quicker your PLB will be able to reach a satellite, so if you're in a narrow gorge or canyon, move up or downstream to an area with more sky visible, or try to get to higher ground. I know of a rescue in a canyon where the first PLB was set off where the incident occurred, then a second one was activated a short way up a ridge. It took an hour or more for the canyon PLB to be picked up, but the ridge one was picked up almost instantly.

In this incident the PLB was taken to the top of the ridge to set it off.

Aardvark wrote:However, due to the number of false applications (that is PLB's set off by accident or otherwise), authorities might wait for two satellites to pick it up before acting.

No. A 'false activation' is when a PLB is set off.. but there is no emergency. This is where the contact is rung and they confirm the person is on a journey where the PLB could be used and give some indication of the planed route. On the older system there was no contact so there could be no checking.

Waiting for a second satellite says nothing about 'false activation'. Example - Talking to one of the chopper pilots, they had an EPIRB activation on land .. track it down to a small boat being towed behind a car.. they landed on the road and stopped the car .. found the EPIRB had bounced out if its holder and been activated. No matter how many satellites you wait for .. the activation may be 'false' or real. By using a contact they can say there is no journey being conducted and probably contact the PLB/EPIRB owner to get them to check...

-------------------------
The 3 hours is not necessarily a chopper .. could be a light plane, or the local cop. And this is for anywhere in mainland Australia.. e.g Cape York etc. In fact a local cop was called out to a PLB in Lichfield National Park.. found a tourist couple stuck in a hired 4WD .. they did not know how to engage 4WD... words were said to the hire company.