Flying with an autistic toddler, HELP!?

you could always ask your doctor, he may be able to prescribe a very light sedative maybe, so your son will be calm throughout the flight. you could also try to keep him awake for several hours before the flight so maybe he will sleep a lot easier on the plane. bring his favourite toys/music to keep him amused for when he is awake, and maybe have a word with the flight staff to pre warn them just in case he does kick off.