Interesting to note that Andrew, Wills and Harry all went a technically difficult flying path and all three did well!
Back in the dim and distant late 1950's/early 1960's one did need a respectable handful of 'O' levels and possibly an 'A' to go straight for a commission on joining but, having joined as an OR, then once one had passed ACE 1st Class and was suitably recommended, one could apply for a commission, even Cert A part 1 and 2 in the cadets was counted towards a commission!