I have wondered this myself, particularly when it comes to aerial searches since line-of-sight can greatly extend the normal range of these radios. SAR authorities will generally try to ascertain what kinds of clothing, food, and equipment lost people have, right?

Assuming that SAR is notified that I have a FRS radio on Channel 1 (for argument's sake), I wonder if the aerial searchers can take advantage of that? Can their radios access that band? Alternatively, I suppose that they could take a FRS radio up with them, crank up the volume, and hold it next to their ear to hear over the noise of the engine/rotors, but is that actually practical for them? I have no idea. I would like to think that a small, inexpensive, license-free consumer two-way radio can help, but practically speaking, maybe it's wouldn't. Dunno.