IO
“A transponder is something else. There aren't any portable models I know of, so it has to be a certified installation”
Not sure what you are getting at, but installations on LAA and some BMAA aircraft are not “certified”.
“Only a tiny % of owners have the contacts to get something installed by a friend who has the authority to sign it off; these are free to source their own stuff from the USA.”
There are about 1000 such LAA installations in the UK, and a number of BMAA equivalents. I installed my own and have helped two people with “low” electric aircraft install second hand items for “occasional” use. Such installations can be signed off by an LAA inspector at little or no cost. Almost all Gliding installations would need to be fully certified and backed by the manufacturer which adds another hurdle and considerable cost.
Pace
“I find it madness that aircraft of any type are allowed any where near cloud without a radio. We are not back in the 1930s. Handhelds are plentiful and cheap.”
No comment on “near cloud”, but it is not possible to make a Handheld work in some aircraft, particularly if it is fitted with S4 mags. I tried for over a year in my Nipper and gave up.
Rod1