The posts about re-enlistment are likely to be correct. However, there were also cases where some aircrew remained in the service but did not stay as aircrew in 1946, when the war substantive system ended. These people went into ground trades, retained their flying badges but not necessarily - unlikely in fact - their former (war substantive) rank.
The RAF introduced the new trade structure which graded aircrew NCOs differently. This used the names 'X' cadet, IV, III, II, I and Master 'X', where 'X' equals an aircrew skill eg pilot, navigator. The badges of rank were a laurel wreath with various stars and an eagle. The whole thing was massively unpopular and in 1951, the RAF went back to traditional ranks with just the Master Aircrew title and badge surviving.
The 1951 trade structure also split ground NCOs into technical and command streams, brought in the ranks of senior aircraftman, junior, corporal, senior, chief and master technician and brought in List One and Two Trades. Aircrew got their stripes back and technicians wore theirs with the point of the chevrons uppermost.
That structure ended on 1 April 1964 when, inter alia, Aircraftman/woman 2nd Class was abolished as well.
Old Duffer (formerly AC2 Young Duffer)