The only airline I know with a formal COS (customer of size) policy is SWA. If you do not fit into your seat, and the flight is full, you have to purchase a second seat for half the price of your ticket. If the plane is not full, then I do not think you need to buy the second seat.

I entirely agree, and I have 56 inch shoulders and am no small guy. I have never needed a seat belt extender, althoguh I have been seated between two guys that did.

I was on an ERJ EWR-MKE that had a lady that had to be close to or in excess of 500 pounds, She was not only taking up most of the seat next to her (1-2 cabin) but was spilling out into the aisle. The part that I found really hard to deal with was the odor. I can only imagine what the person next to her, ir in back of her was dealing with. I was across the aisle and 2 rows back.

The question here is, where exactly do you draw the line between accomodating a person of size and trampling on the other passenjare? It's not an easy answer and I sure as hell wound not want to be the guy having to make it.

I do think that if you cannot sit into one seat and the plane is full, that the others shouldnt be forced to deal with that. I do not think that it is unreasonable to ask someone who is so huge that they cannot confine their body mass into one seat to wait until there is a flight with two seats open.