Any suggestions to manage incontinence on an airplane?

Forgive me, but I thought "have to fly mother... brother's funeral" was a moot point. I thought you were trying to come to a practical decision about whether or not this was a good idea.

How did you come to the conclusion that you do have to do this, just out of curiosity?

If you really do have to, then I should get in touch with the airline's customer service team as soon as possible and ask for their help, approaching your mother's requirements as they would those of any other person with disabilities. And, by the way, I wouldn't try to do this on a budget - pick the best carrier your mother can afford.

You don't "have to". Leave her home. If she messes before the flight, she may be banned. During flight is a hassle for everyone in an enclosed capsule. You both cannot fit in the lav.
She does not walk so who is going to carry her into the plane? No one. Have you ever seen this scenario on a plane before?

You can hire a fixed wing with a stretcher for 60 grand or so

You are posting the same question from July 23 and the overwhelming majority posted no. Why the denyal?

Doubling and tripling the diapers has been suggested, but in reality, you both won't fit in the bathroom at the same time.

Not only would you have to fly her there with all that entails you then have to fly her back.

Given that she is in AL I wonder if you have any experience helping her change and clean up?
If you are determined to do this I would suggest she wear a double (triple?) layer of incontinence pull ups, or maybe a tab style brief inside of a pull up, that way the inner layer could be removed (by tearing open the sides) without having to change her clothes. Baby wipes are a must for clean up.

Lots of answers on your previous post, you do not have to fly your mother there. Think this through, this makes no sense. The other people on the plane do not need to be inconvenienced by the odors of a full diaper as you will never get her to the bathroom and if you do it is too small for two people.

Keepurheadup, when was the last time you have flown? The middle aisle in the plan feels like it is only one foot wide, so if your Mom is in a wheelchair, I don't know how the airline handles getting a passenger to their seat.

Unfortunately with incontinence, it is only fair to the other passengers who are sitting nearby if the person can go to the restroom and change their undergarment. Sadly, said restrooms on a plane barely have room for one person :(

I think I would think twice about flying mother. The logistics are so complicated.

You were given lots of advice on your other thread. Are you sure you can handle your 88 year old incontinent, immobile mother on your own? You need to worry about more than just the plane ride. Have you considered Skyping or having a relative record the service?