Rainboe, Impossible!
You join the RAF at 18, spend 4 months in Officer training, 3 years in flying training, not sure the routine theses days but I did Jet Provost Mk3 0 13 months, JP Mk5 4 months, Hawk AFS and TWU, 15 months, OCU 4 months and then Ops training on squadron, 3 months, Add in holding time, combat survival, Avmed etc etc and you can just do it before your 22nd birthday - if you are lucky!