Someone on here (of Flyer?) kindly posted a link to a PDF document which contained the whole of the UK airspace with no other terrain or cluttering detail (other than towns).
In the plane I carry a laminated version of this for the South and around London (if I go oop North, I'll make a new one
) . It is very very clear from this the airspace limits (rule of thumb around London < 2500 and you're ok Class A wise while outside the CTZ -
Don't forget the D though !!!!!), and is handy as a cross reference.
Making mistakes is ok, but really this was a basic mistake, espcecially with 3 pilots onboard. If I fly with someone or they fly with me I'll look at the map too and cross check where we are, and the airspace just to be sure.....On my map, I also mark "BELOW 2500" in big chinagraph when the TMA drops, as an aid in case I forget....