Hi
@gleeb, I travelled to USA with my wife in 2016, just after her Alzheimer's Disease was diagnosed. She didn't have any issues with incontinence but I can see how difficult it would be on a plane, not least that there are times when toilet facilities are unavailable. It never occurred to me to identify as needing assistance or pre-boarding. I needed to be extra vigilant going through security and passport control, checking her progress and ensuring that she left nothing behind. Newcastle is a relatively small airport. It might be more difficult at a bigger terminal. I did have to stand guard when she went to the departure lounge toilet in case she turned the wrong way on coming out. But I had to do that for years before dementia was in the mix.
I had booked aisle and centre seats to make it easier if either or both of us needed to get up during the flight. Once on board she spent most of the next 7 hours talking to the chap in the window seat and ignoring me. I was grateful for his patience. On landing at Newark she asked him if he had been to Newcastle before, almost as if the flight had gone unnoticed. It was only as we got off the plane that I noticed that she was wearing knickers over her trousers, a foretaste of later difficulties in sequencing and dressing appropriately.
Our apartment had a rooftop view of the Empire State Building but she insisted that we were in Gateshead. She did say that she was leaving to walk home one night but intervention by her son dissuaded her. We would not have gone so far if it wasn't for the fact that he was working there and was keen for us to visit.
How much of our daily activities she appreciated is debatable. Ellis Island seemed to interest her but she had forgotten about it by the evening. Yet. despite some bad temper and small crises, I enjoyed the holiday. At least there was no repeat of losing her in the middle of the night when she got locked out of our hotel bedroom, as had happened before. By the time we were home, though, I had resolved not to fly with her again. We did have some good holidays in the UK for the next 2 years before it all became too confusing for her.
All of which is by way of saying that what might happen on your flight and holiday may include any or none of the above. It rather depends upon your husband's capability, your patience and ability to deal with the unexpected.