Aviator means someone who flies, as a pilot. It's been the dictionary for longer than the RAF has existed. 'Specialist' doesn't work as the collective noun as it isn't exclusive to the air force, or even air power. 'Leading Specialist' and 'Senior Specialist' (but not Senior Air Specialist because of the abbreviation...) might work for ranks, but not the collective term.
While an abuse of the original etymology behind its creation, 'Ardian' might work, albeit it was originally proposed for officer ranks in the list which was drawn up when the Admiralty (and to a lesser extent the War Office) objected to the use of their ranks for the new service, but which wasn't implemented.
It is gender neutral, has some heritage and tradition behind it, although it is, of course, obscure and as the word (a combination of two Gaellic words) loosely means 'Chief Bird', it is clearly aviation-related, but doesn't suggest one who flies an aircraft. And using the 'primary provider of the UK's air power' mantra which was fashionable a few years ago, it fits with that, too. Finally, humans are higher in the pecking order (sorry....) than birds when it comes to the food chain, so 'chief bird' might work, just about, in that sense as well.