I'm confused. I could see why "semi-permanent" Transceiver installations could be an issue re "approvals" after all the same applies to panel mounted installations for which all sorts of approvals and licences are required but what's the problem with a handheld for emergency use? I agree with WR. If you have a radio failure and then respond to the ATC unit on a handheld how is anyone going to know whether the unit is approved or not? Does the CAA have a transceiver detector van?
Better to be heard on anything than not be heard at all.