Mike that Tristar was flying a unserviceable engine. Sometimes, if an engine is needed at the destination, there is a special mount that they can mount the engine on. This was commonly used on the 747. For more info, just look up ferrying engine unserviceable
cupcakefairy87 I think the same. Can't remember, AirFrance operated this plane. At least the first AF picture in this video isn't real, cause of the new logo.