Duncan Sandys 1957 White Paper on Defence ended NS aircrew training and for those on short service commissions of less than the full 5 years.
For those already in the training system would continue until passing out of their brevet courses. National service aircrew would then be released at the completion of 18 months service with option to recall without notice at any time to complete any outstanding service.
By October 1959 there appears not to be any NS aircrew left in the system.
However I still wonder if I remain under that option having just read
ORAC's post
Rebirth of Conscription