Ride of the valkyries easter egg in Battlefield 4 + suprise

How to trigger 1, get the M60 ULT 2. Fly from just outside the bounds on highest altitude over the US base with 1 more guy in the heli Dammit i totally fucked up the scaling of my font :D Also not sure who exactly found it, proper credits coming soon (tm) My twittah - My PC - I like cookies! Do you?