Hello. Do contact some local and foreign airline companies to see what the basic requirements are currently. Get in touch with the royal air force as well to find out some more important essential key details. Make notes on the job in preparation as part of your level of effort. Do some research online using quality trusted websites like Glass door to learn more.
Be prepared to also undergo lots of very hard on the job tests once you qualify. Also pay careful and close attention to the standard basic eye sight criteria too. In order to be fully and completely prepared make sure that you focus on key skill development. Another good option is to investigate a few different cool jobs at the airports across Britain first to gain the needed level of airline experience in question. Read some useful interview preparation and career development articles online. Consider other possible entry routes and look at alternative job options. For example a head or junior new flight attendant, a scheduler, security personnel, ground worker, plane food preparation, porter, car hire, airport shop worker, flight ticket scanner, foreign language translator etc. Take it from there.