On the new Nazi zombie map on cod world at war on level 15 does a zombie come from a plane with a machine gun

my question is how do you get the new nazi zombie map Berta: You have to download it from xbox live. No zombie come with a machine gun. I been past level 15 a bunch and no such thing has happened What a load of crap!

If u want to know entire storyline drop me a message! ( Connman96)