|This mission is one of the two setup missions required for the obvious approach of The Big Score mission. It is marked on your map as "Hs" after choosing the Obvious Approach.|
When you head to the train station at the beginning of the mission, there should be two guys there working. One is outside by the train tracks and the other is in the tower. Kill them both and then use the controls inside the tower to switch the tracks. Go outside and wait for a train to pass by before you switch to your other character.
Fly the chopper over to where the freight engine is located, and line it up so you can pick it up with the magnet. Once you have it, bring it back to the airfield and you'll need to drop it onto the trailer. Remember not to move with the left analog stick and turn with the shoulder buttons. When you're lined up with the trailer, drop the freight engine and go back for one of the flatbeds. Drop it onto the second trailer to finish the mission.