Without a doubt the rappel or rope descent is one of the most stressful parts of canine search and rescue. It is stressful for the handler, because rappeling with a dog strapped to your body is not an easy thing to do. But it is even more stressful for the dog, since she does not understand what is happening and is hanging many meters above ground with no control whatsoever.
A certified SAR canine has to stay calm, follow her handlers lead and most of all be able to work after. It takes a lot of training and an awsome prey drive to work a search after a 50 meter descent.