Some of you 'pilot' guys display amazing innuendo & assumptions !
In practice such radios have been in use for years (on 25K/cs spacing) as pilots and the CAA know very well.
Many light 'planes and flex-wing a/c have 'hand-held' radios that work consistently well.
If you cared to look, you'd see they get 12 volts supply off the a/c & naturally have an external aerial plugged in and headset adapter with PTT.
Just like a real a/c radio !
And as for mounting - again methods for attaching them safely have also been developed - so have no fears for we light a/c flyers.
It's simply the CAA accepting the status quo & knowing safety is enhanced by proper use of the airwaves - your imaginings describing likely perils need not have been disturbed.