Hawaiian 717 must have sucked a coconut, they dropped the engine right here next to the passenger boarding area. It's not quite Ice Pilots.

I had this happen once in Chicago, I think it was. The flight was delayed, and the lady at the counter announced that they were "double-checking some technical things" on the plane. As she's talking, you could look behind her through the window and watch as the crews detached the starboard engine and carted it away. Pretty funny. I was amazed at how few bolts hold those things on. Within an hour or so, they'd put a different engine on, and taxied the plane around to test run it.

I don't think most of the passengers even noticed.

747's used to carry a spare engine around with them. They had a lot of trouble making the engines last very long.

Five engine 747
http://www.airliners.net/photo/0606488/M/

My Dad was friends with a retired TWA pilot. He gave us a tour of the maintenance hangar in Kansas City. I think I remember only three bolts holding a 747 engine on. WE got to go inside the L-1011 simulator also.