Mutty,
you've clearly been out for a while. These days, the ADC would be a Sponsored Reserve from SODAMBACO Umbrella Solutions Consortium who provide the umbrellas under PFI arrangements at a through-life cost of £1.3 million each (CEO a former Air Mshl); The SRs are mainly ex SP (at present) with a discounted salary as they are in receipt of a military pension. However, in 5 years' time the ADCs will be Eastern Europeans with chunky boots and dressing like boat people. And don't have a Scooby about military ethos, terminology, history...but are much cheaper to employ.
And if you think I'm joking, visit the Mess at High Wycombe.