I flew up stairs with rocket and elytra, crashed into piston door and died. I spawned at bottom of stairs and walked up to collect my stuff, triggering the pressure plate that opens and then closes the door on my way up. Entire inventory other than equipped items, including enchanted armor, shield, and elytra, which was nowhere to be found. It was not dragged into a gap in the door's Redstone or pushed through a wall or floor, I checked.