When our AS son was younger we always holidayed in the UK.  The prospect of even a short flight seem fraught with risk - the long wait at airports, crowds, queues and the whole sensory experience...thats before you even get on the plane!    Since he hit his teens and his understanding has improved, we have dine some short haul flights - thankfully will no problems.    All airports now offer assistance if you are travelling with someone with a "disability" and we have used this a couple of times with mixed results.

This is our experience - firstly only the child and one carer often receive the special assistance,  meaning that if you are travelling as a family you are likely to be split up with the remainder of the party taking the "normal" route through security and possibly not being reunited until you are actually on the plane.  This may not be an issue but if you have not pre-booked seats, making sure you are all seated together takes a bit of negotiating.   The main issue I found was getting myself and my son through the security scanner -  as we could only go through one at a time.  Do I send him first and hope he doesn't wander off when he gets through or do I go through first and hope he follows?!   Much easier to do this as a family - send Mum through first to receive him on the other side!

We also found the service at UK airports better than the ones abroad.   At one airport my son and I literally had to wait in a corridor for 1/2 hour whilst my wife and daughter enjoyed some duty free shopping!

One of the really helpful aspects is prior boarding - no waiting in a long queue to board.    We have used Airport Assistance on 2 trips now (so 4 times in total) - the last time my AS son was in a wheelchair having broken his ankle - so assistance was essential.    Now that he is fully mobile again we won't bother using Airport Assistance finding that some forward planning (pre-booked seats and online check in) can help to ease the process anyway and means that the whole family can stay together.   The one area that is always fun is security where his lack of social skills and awareness can bring some funny looks - but we are well use to that by now!  Happy holidays.