I got put on quad track when I was 17 which was a ludicrous learning curve being asked to cultivate and subsoil on rape I think we were farming 1400ha at the time! Dad used to come and he would move the quad between farms whilst I escorted it. Good times!He can legally drive any tractor trailer combination on the road at 17 and as long as he has also passed his car test.
However, just because it’s legal doesn’t mean I will let him. He will need to prove himself in the field and show himself to be mature enough to take the job on. Even then he will be escorted by me on front on the other machine.