First-time scanner for a 5 y/o (and Dad)

Simply looking for a cost effective scanner (I think), advice sort please.

I am new to the forum but not new to watching planes since our 5 y/o never lost his love of planes.

We live 12 miles from Manchester airport (as the crow flies) and so are lucky to have planes fly over us at a comfortable 2,500 to 4,000 ft (thanks to the Pinkfroot's Plane Finder App for the info!!) --they are high enough not to go unnoticed, but low enough to spot if you are looking :)

For Christmas I was thinking of buying our son a scanner - which I understand is a radio that can listen on medium wave to pilot's comms.

Is this realistic to be used at home, based on the height of planes or am I missing the point here?

We do regularly visit the Manchester Airport viewing park, so if the scanner will only work there that would still be a good purchase.

Thank you for any help.
Of course you can listen to radio frequencies from planes etc. and in fact a small scanner with a simple antenna, even a metal coathanger is sufficient, but before doing so, I would advise you to check your local legislation. As far as I know, its not allowed in the UK to listen to it...
Wow! Really? I thought that is what scanners were for? ...from what I have seen I can buy a scanner at the local airport viewing park (Manchester MAN) --these appear not to require an antenna other than the one connected to the handset --looks like an old-style mobile phone.

Have I misunderstood?
So, what is the norm - what do most people do in the UK do to listen to air traffic/pilots on a budget?

The scanners they sell are 'modern' --they have digi display and keyboard with a stumpy aerial.

Is it a case of one of those oddities: they are legal to own but illegal to use?

I remember as a kid holding a radio whenat Manchester airport, probably using AM or something and hearing 'the pilots'.
It is illegal to listen Government,emergency services and so on. But if you do it discreetly you'll go unnoticed. Obviously if at the park there is no one with the scanner out don't take it out! I found the ICOM IC-R6 very reliable and a very wide range to listen to! 1Mhz to 1300Mhz