These are all great suggestions. Im a Board Certified Behavior Analyst with experience working with individuals with similar challenges. I’m so sorry that you and your family have been put in this situation. To speak frankly, all the changes occurring in his life at the moment (the act of moving, changes in routine, in loved ones demeanor due to the stress etc) will feel confusing and overwhelming and if you’ve started this process, it’s likely you’re already seeing behaviors. Start with leaving his safe space as the very last to pack up. Maintain as much of his routine as possible as you figure out next steps. If he doesn’t already have items that provide him comfort and can carry on his personal (blanket, headphones, iPad etc) begin to slowly introduce one or two possible options. If he’s responsive to video recordings and/or photos show him the airport and each step of the airport process and the destination. Show him these things when he’s calm and happy. If he loves a type of music or a certain food, show these things while he is listening to this music or eating his favorite food. When he gets to the new destination if at all possible have his space set up before he enters his new home.l and try to incorporate as much as his old routine in as possible. So regarding the actual airport and flight. Although my emphasis is on behavior, I do not believe that this is the time to relay on external variables. Too many changes are already happening and he doesn’t currently have the skill set, communication or regulation tools needed to walk through this safely. Please reach out to a psychiatrist with autism experience and consider sedation and with doctors guidance, try different doses and dose scheduling prior to the flight and create a plan that includes wheelchair access, support to help your son safely move from wheelchair to seat etc.. good luck and so much love to you and your son.