Other reference in the episode 6 is Sanya singing jazz:
Schräge Musik, derived from the German colloquialism for Jazz Music (the German word "schräg" literally means "slanted" or "oblique"; it also has a secondary meaning of 'weird', 'strange', 'off-key' or 'abnormal'), was the name given to installations of upward-firing cannon mounted in night fighters by the Luftwaffe during World War II. This allowed them to approach and attack British bombers from below, where they would be outside the bomber crew's field of view. The British bombers of that time generally carried no defensive guns in the ventral position. The ventral turret fitted to some early Lancasters was sighted by periscope from within the fuselage, and proved of little use - the fitting of a Sperry ball turret of the kind fitted to the B-17 Flying Fortress and B-24 Liberator would not have been practical as the British bombers had not been designed to use them-and sighting a target at night, for the ball turret gunner to aim at, might have been a problem as well.