When you got to Sub-Junior (Year 9) in 1958, the year when most of us turned 14, you became eligible to join St Laurence's ATC (Air Training Corps).
I say "became eligible" but you had to have a pretty good reason not to join, like parents vehemently opposed to it.
Lauries was very proud of having the largest ATC in Brisbane and maybe in Queensland. This was achieved by having only Air Force cadets (no Army or Navy) and pretty much compulsory service.
We were organised as a Wing, which comprised two Squadrons, each of which had three Flights. A flight consisted of around 20 to 30 students.