I showed this to my little brother who thinks of himself as a bit of any inventor and here's what he said:

" It would be cheaper, faster, simpler, lighter, to build parachutes into backs of seats. Then a huge back door opens, like a military cargo plane, all seat belts lock and all seats on rails automatically slide / roll out the back whether screaming passengers like it or not. All thin passengers sitting next to fat passengers are equipped with tasers incase fat asses try to hold on to others parachutes. If it's a full flight with no seats left then pilots ask fat passengers if they will help them for a moment in cockpit, then lock door on them and take available parachute seats. After everyone is off plane (except fat asses) pilots press self destruct remote so plane disintegrates into smaller parts before hitting ground. Because lower class passengers go out the back first, the final business class passengers can throw something onto the seat rails and jam them so first class 1%ers get stuck. Win, win. "