If I recall correctly, didn't someone get a year inside for using a mobile phone in an aeroplane? Prosecuted under Art. 55 of the ANO as it pertained at the time.
I don't doubt it for a moment.
In an
airliner.
The cabin crew tells you to stop it; you refuse, probably (because you've just had 3 pints of beer) make some derogatory comment about her skirt, and since the flight has not yet departed they call the police and you get taken off and "sorted out". Coppers at airports like nothing better than a bit of employment.
This is half the problem here... people are getting mixed up between being naughty on an airliner and breaking some rule which is prominently plastered all over the place, and being naughty in the privacy of their own plane where nobody is going to catch them.
There is a mass of regs in the province of the Radiotelecommunications Agency which few people care about. For example you "cannot" use most of the VHF transceivers on the U.S. market because they are not CAA approved (the RTA has delegated the approvals of aviation related bits to the CAA, who probably in turn sub out the job to some commercial lab). I am sure this is true but does it relate to anything real? Some of these can record the audio and play it back; this is supposedly illegal in the UK but who actually cares?
I would not make voice calls airborne because they rarely if ever work, and I don't listen to music because I find one is busy enough with ATC (and my intercom's music input feature mutes the music when there is any radio activity so unless flying non-radio one gets constant breaks). But this is different from saying something is illegal
and there is a good reason for it being illegal.
If I really wanted airborne voice calls capability I would get the satphone connected to the intercom. Can't see the point though, when one can do texting with the satphone very easily.