I was riding with a group of Mountain bikers who were riding on the scenic “The Old Ghost Road” Mountain Bike Track in the South Island of New Zealand. I had been included into the trip after one of their group had pulled out. We were all riding along the fairly technical “Torr” section of the trail when Angus, who was two riders in front of me, stalled on a rock, lost his balance and tipped off the side of the track.He tumbled about 8 meters down and then over a lip onto a jagged rock ledge. His bike carried on over the edge and fell a long way further. There was no response when we called down to him, and we could not see him on the ledge, so I gave my PLB to one of the group and gave him instructions to take it 100m further along the track where I knew there was a spot a helicopter could land, and to set it off. Meanwhile I was able to climb down to Angus and ascertain that he had severely broken both of his wrists and also one of his ankles. Some of the others came down and between us we were able to stabilize him and somehow managed to get him back up onto the track and along to where the rescue helicopter would come. 40 minutes after activation the Helicopter arrived and the Paramedics took over and gave Angus some much needed care and pain relief, he was not in a good way. Once in the helicopter they flew him to Nelson Hospital where he has been making a good recovery. The rest of the group rode out as planned. Had I of not been included in the group last minute there would not have been a PLB among them. and things could have been much worse. The boys are all now looking at getting their own now that this has happened! You carry a PLB in the bottom of your pack and forget about it, never wanting to have to use it, but when the time comes and you need one, you are really glad you have it!