United Airlines Passenger Destroys Seat Before Other Passengers Zip Tie Him

This is no way to score an upgrade -- new video shows a United Airlines passenger standing on his seat, furiously kicking and trying his level best to destroy it.

The man flew into a full rage during the United flight from Austin to L.A., silently doing all he could to smash his coach seat to smithereens ... while other passengers on the flight watched in horror, no doubt wondering what the hell was wrong with the guy.

Decked out in gray sweatpants, the unidentified flyer's bizarre violence streak continued until another passenger, Gino Galofaro -- who recorded the Nov. 16 attack -- stepped in to hold him down. Gino says 2 other passengers ran to get zip ties, and all 3 of them eventually restrained him.

It's unclear why the flight attendants didn't engage the man -- the plane was reportedly about 40 minutes from landing at LAX when this went down -- but police were waiting at the gate when they landed.

United says it's taken the "no duh" step to ban the man from all future flights.

Gotta say ... as uncomfortable as they tend to be, that little seat held its own against the barrage of kicks.