During the Tug Of War level Flughafen, there is a glitch when playing as the Allies. When you spawn in the Allies zone, go behind the first hangar next to you, hugging the right wall the entire way. When you reach the end of the hangar, there will be a slight turn. After that, keep hugging the wall and eventually you will go into it. You will then see a ledge. Fall off and you will be underground. Only the top of your head will be visible. Note: This cannot be done if there is a tank standing in the way.