ELT's are notorious for failing to operate in a crash, either because they are destroyed or fail to transmit for any of several reasons. The newer breed of COSPAS 406 MHz ELT's are more reliable and some but not all transmit GPS position info within a few meters. Good idea is to carry one or more PLB's (personal locator beacon) in addition to the ELT. These also work on 406 MHz and virtually all have an embedded GPS to transmit position info. These are now quite affordable (about $250 U.S. an up) and a case can be made for having one for each seat in the helicopter. However, PLB's depend on a survivor in a condition to deploy them. Perhaps best of all is a real time satellite based tracking system such as SkyTrac or Spider Tracks (there are many others). These are independent of the aircraft in the sense that if the transceiver in the acft fails to provide a position report every minute (this time interval is adjustable), alert messages are sent from a central monitoring station to a list of user selected parties (SAR, company, girlfriend, etc). Someone will know withing 1-2 minutes that something has happened and where it happened.This kind of system is also quite affordable, with initial equipment cost starting below $1000 and monthly service charges ranging from $30 per month and up depending on usage.
Last edited by EN48; 6th August 2015 at 19:22.