In deciding whether to buy a locator to augment the required ELT it is
important to know the difference between a Personal Locator Beacon (PLB) and a
tracking and locating device.
The PLB emits a 406 MHz signal sent to a satellite that is
continuously monitored. Activated PLB coordinates are sent to the Air
Force where search and rescue services are coordinated among feds
and locals. There is a one time cost for the unit and its registration
is free and monitoring is free.
A locating and tracking device (such as the Spot) is sold as a part of a
service offered by a private, free enterprise company. The company
provides services including notification of search and rescue services in the
event of an emergency. As Fred correctly says, other services include
monitoring of the device location that can be monitored by the user or anyone
else on computer, IPOD, or web accessing mobile devices, etc. The cost of
the device is less than the cost of a PLB but the tracking and locating services
are sold as an annual subscription. Locating only is the least expensive
and tracking is more.
Most importantly, both the PLB and the locating and tracking device must be
activated manually by the user. This is a critical point
since activation is designed to be somewhat complex to avoid setting it off
accidentally. I you are injured and/orunconscious or you can't get to
or find the device, you're out of luck.
I chose the PLB because I was not interested in the tracking
services. The soaring community and others clearly have good reason to be
tracked. I, actually, prefer that my wife not know where I am while
flying.
I expect that the PLB service may outlive the companies that offer locating
and tracking in this fragile economy. And as after a year or two of the
locating and tracking subscription, the prices equalize.
Finally, it is unlikely that either of these options will be adequate to
meet any regulation the FAA may issue to require a 406 MHz ELT's to replace the
121.5's ( which are now obsolete).
I hope this is helpful.
Dan vdM