[jimworcs]

It is not "appeasing" special groups. Society is made up of a whole range of people, tall, short, fat, thin, able bodied, less abled, elderly, babies etc. When you start to pick out one group, you will eventually target them all. There was a poster on this site who recently advocated banning children under 5 from flying, others object to fat people, disabled people, etc.
Airlines provide a public accommodation and should be pragmatic about ensuring that they accommodate as many of the public as possible. Over 30% of the US population is obese or clinically overweight, so this is not a small number. In addition, the overall size of the general population in terms of height and weight (even when in proportion) is considerably bigger than it even was 30 years ago.

The seat width, pitch and the average weight calculations for the passengers need to be revised to account for this. (The FAA has modified these calculations for small aircraft, after the weight of passengers was a factor in an accident in CLT, NC).

There are already accommodations for people with disabilities.. no one is advocating wider aisles to permit wheelchairs. The issue is that the accommodations should be made. Likewise, obese people don't need a special seat. The pragmatic solution is to leave the seat next to them empty if the flight is not full. If the flight is full, require the obese passenger to buy a seat, along the lines of the Southwest policy. As long as this policy if fairly applied (as it is on Southwest), I can see no problem with that. I speak as a fat bloke myself. Gate agents can simply hand the passenger a sheet outlining the policy and requesting that they buy a seat. If necessary they may have to booked on a later flight if no extra seats are available.

On the issue of how it is applied: I recently went to Alton Towers (a theme park in the UK). The issue of whether obese people can fit into the seats for the big thrill rides is obviously a problem for them too. It is resolved by them having example seats dotted around the park. People can try out the seat and see if they are able to lock the clasp before going into the queue. This was not humiliating..as lots of people tried the seat, whether they were fat or not. What is to stop airports having a standard row in the terminal which people can try out and see if the armrest comes down. This is an objective and fair measure and I cannot see what the objection to that is. It can only work if it is uniformly applied by all. For that, I think we need rule making by the DOT, similar to how they handle disability rule making.

There are usually common sense solutions to these problems, but this is interfered with by people who spend their whole life being angry at things. The posters on here who write things like "why should we do this or that" for fat people, disabled people, etc, are very short-sighted. There but for the grace of god...