In this game, Ellie has to get to da choppa, and for some reason this helicopter that has crashed in the middle of the USA is from the Swiss air force:
Maybe Switzerland tried to provide aid in the post-apocalypse. Probably helped by Iceland, in order to get that chopper across the Atlantic Ocean.
For reference, here’s a real Swiss air force chopper:
And here’s the Swiss-American chopper from the game again, also with a Swiss Cross on its belly:
Screenshot from igcompany’s playthrough.