In response to your original request about airlines generally, and a CAA List try
http://www.caa.co.uk/default.aspx?ca...=90&pageid=340
Most of the helicopter AOC holders appear in the type B operators list.
http://www.caa.co.uk/default.aspx?ca...=90&pageid=508
There's a fairly comprehensive list of weblinks to helicopter operators here
http://www.griffin-helicopters.co.uk...OC%20Operators
V.