PLB response time

I’m curious as to roughly what sort of time frame it takes for help to arrive after a PLB is activated. I understand that helicopters need visibility to fly so if you are in cloud the response will be coming on foot (which can take considerable time) and even when the weather is suitable for flying there has to be a helicopter available. I know two people who have taken tumbles that have resulted in serious breakages who have activated beacons. For one rescue arrived in the 1 – 2 hour time frame for the other it was 3 – 4 hours. Hopefully I never have to use my PLB but if I do I don’t want to have unrealistic expectations on how quickly help will arrive. What experiences have other people had or know of?

one very public incident was on mt taranaki when two climbers were trapped on top , the weather prevented rescuers from getting to the climbers for days. rescues around arthurs pass are listed here to give you further idea of time variances in effecting a rescue http://www.arthurspass.com/index.php?page=278

This might help: http://beacons.org.nz/ActivatingaBeacon.aspx#How%20Long If the celestial equator is masked by terrain, then it could be anywhere from between 30 minutes and 5 hours for the signal to be detected by a low-earth-orbit satellite. Also see the following question about how soon help might arrive.

There may also be others ahead of you on the 'needy' list for that particular chopper at the time. Our group got growled at for moving someone with a dislocated knee away from the landing site, as he'd been waiting most of the day and the thinking was about possibly overnighting.

So rather than ringing the cavalry its more like sending them a postcard saying wish you were here

Was involved with a helicopter evacuation for a party member that had tripped and suffered severe internal injuries (cracked ribs, ruptured spleen, internal bleeding) from the Orongorongo River in the Rimutakas this past Waitangi weekend. Time for helicopter arriving from contacting Police via cellphone was about 1 hour. The weather at night was fine and clear. One other incident I know of was a party of 4 were stuck in the leatherwood below Tarn Ridge hut in the Tararuas and it was over 24 hours from activation of the PLB to an arrival of a helicopter. The party had to wait out a storm that dumped 170mm of rain overnight. @izogi has more of a write-up here: http://www.windy.gen.nz/index.php/archives/5117

Response time for a GPS equipped PLB will be quicker - it sends a signal which includes exact location to a geostationary satellite which beams it down to the RCCNZ. Something should start beeping in there almost immediately. If not GPS equipped, there is no position till a lower orbiting satellite comes overhead and establishes position from doppler effect. It could take several passes by different satellites to get a good enough position to work with, so it may take a number of hours. Response time after that depends on how quickly they can get something in the air. Could be a long time / impossible in bad weather night. Can be very quick in the right circumstances. An example of quick response was when Charlie Whipple put his yacht on the rocks on Great Barrier, was able to grab his PLB and jump / swim to a rock, activate it. Helicopter was overhead in flight time plus only about 10 minutes. http://www.duckworksmagazine.com/08/reports/resolution/

By the way, the geostationary satellite that is likely to pick up a signal from NZ is on the equator and to the east of us out over the Pacific , so it might be worth trying to get a PLB in a position where it has a view of the sky to the north east if you are in a narrow gorge or on a steep south west facing slope. At the bottom of a bluff that faces south west it could take an hour or two longer to get a signal out but one of the low earth orbiting satellites should still pick it up once it comes past. It is extraordinary how quickly it is possible to get help now days in the right circumstances. There was a situation a while back with a kayaker capsizing on the Hollyford river bar, getting swept out to sea, activating a beacon and being picked up by helicopter. I've been on the verge of similar trouble in remote places a couple of times in the past and it's been a pure choice of getting out of trouble on your own or not getting out of trouble at all.

PLB/Epirbs use 2 types of satellites the first is geostationary at and altitude of 32000km and NZ has fringe coverage of these as they are a long way either east or west of NZ and you need good sight of the northen sky to get the signal through. the second system uses polar orbit low orbit satelites that travel at 2000km per minute at an altitude of 800km of which there are presently 6 operational the maximium time between low orbit passes is 90 minutes. So if you break your leg at the bottom of a steep valley of which NZ has plenty it may take 90 mins before the rescue coordination center is notified. if you want a cost effective PLB that weighs 140grams with a 10 year warranty look at https://www.safetybeacons.co.nz/index.php/kti-safety-alert-sa2g-406mhz-plb-personal-locator-beacon.html

Hi Peter, is that your site you're linking to? No problem just note your interests, thanks.