I would echo ASFKAP's sentiments. Adding that starting at the bottom will involve years of study and working bad shifts in poor conditions to get decent money. If your lad is desperate to mend aeroplanes he will put up with it. If he is doing it because he can't think of anything better, I would stongly advise against it!
Eaven my love of the job is sorely tested at two in the morning with my arm down a 737 toilet in a leaky glove!
TRY to persuade him to stay at school.
Rgds Dr I.