Depending on where you are going, I would talk to jis pulmo and make sure, breathing wise, what you would need to do.
I have been told southwest takes care of pwc better than most but people take their seat cushion from the chair onto the plane, wrap up the control arm etc. Someairlines dont like to take the batteries out of the chair and reinstall them. I know Southwest does. You will need to know what type of battery your pals chair has.Check the airlines accessibility page for these types of answers. Sw helps people transfer to their seat.
Medical equipment like a bipap doesnt count towards your personal item and a carryon. Always carryon the breathing equipment.
When we flew to denver, we loked at renting a wheelchair van and chair. The chairs were about 35 a day and the van 115. Make sure you know what types of vans and chair are offered so your hubby fits.
Supposedly permobil, if that is the brand he has, will loan you a chair. I do not know how this works.
Slaughter, we travel a lot. The main thing is to make sure your rental vehicle is big enough for everything you will bring without having to unload it everytime your pals gets in and out. We love getting away but for the cals it is work. You are doing the driving, packing and unpacking, etc. I always carry a ton of ones and fives with me so if I have someone else, like a valet, to do the work, I can tip them.
Hotels....this is important. If you are staying in a hotel you need to get a handicap room if your pals needs help transferring or will be in a power chair. Hotels are only required to have 1 or 2 roll in shower rooms, and a few accessible with tub rooms. If you make your reservations online, make sure you get this guaranteed. After your online reservation, call each hotel. Make sure they block the room otherwise there is no guarantee.
I have written a book so if you have more questions pm me or ask here! Good luck