Pallan, it's quite possible to have your A level results at the age of 18, depending on which country you sat them. The same is true for Scottish, Irish and various other European students who will have their A level Equivalent qualifications by age 18. In Scotland it's actually possible to have sat the English A levels (rather than advanced higher or CSYS, or whatever they are now) and have your results in hand whilst still only 17. You could also have sufficient Scottish highers by age 16 (I would have, as would half of my school). In that regard, it makes sense to make potential cadets wait until 18 to apply as if they started earlier they could potentially reach 1500 hours commercial flying while still being too young to hold a full ATPL.
Is there any kind of legal requirement to be 18 to start a CPL, or do you just have to be 18 to have one issued? Beats me.
Edit: ok, so I've basically just reiterated much of what G-FORC3 said!
