All good advice above, particularly the medical bit. Bottle-bottom glasses, a history of genuine asthma or too many pies (deep fried Mars bars?) could keep you out (the latter only temporarily!)
Over the last couple of years, potential VR(T) officers have been required to go through OASC, the same as regulars. So young and/or recently commissioned VR(T) on your ATC Sqn (or a nearby one) could give you insight into that particular hurdle to be overcome for an RAF commision (and I imagine the RN is very similar). You have to be commissioned before you get anywhere near an aeroplane as a pilot (in RAF or RN).
Fingers crossed.
