regarding ELT's, those flash new 406's that got forced on us about 10-15 years ago, have a very low activation rate in Helicopters in NZ.
they successfully activate in something like 15% of accidents.... i wouldn't count on them, far prefer to rely on the tracking, at least the search will be within a few square kilometers, rather than, he flew away and didn't call after 30 minutes.... That is a huge area that a helicopter could cover.