We boarded the DeHaviland Twin Otter, a twin engine turboprop that seats about 20 passengers. It was small enough that there was no cockpit door and we could see all the action. Just before closing up the pilot had the six passengers change seats so there were equal numbers of bodies on both sides of the plane to balance the load.
I thought we were ready to take off when the copilot came back and asked us to move again. this time she moved us all to the front of the plane.
Moments later the plane seemed to tilt back slightly and through the rear entry door came one more passenger. I can only assume he was a Sumo wrestler. They searched around, came up with three seat belt extenders and belted him into the rear three seats in the plane (which was the only seating option).
Safely strapped in and balanced we rolled down the runway and lumbered into the night sky as the lights of Honolulu appeared on the darkened horizen.