Aren’t planes required to have PLBs?

Most of us would never be in a small plane going out over the ocean, but it would be nice to know ahead of time if the plane had one and how it worked. Or have your own to take with you.


With the move to the 406 MHz ones, are the 121.5 MHz ones going to still be useful? And they may be coming on the used market (e-bay) and worth a look if they still have a way to be picked up.