I was watching a video of an MD-11 landing in Quito, Ecuador
The crew is German (Lufthansa).
When they speak with ATC it's in English (obviously).
When they speak with each other it's in German (also obvious).
But, when they go through flight procedures, they speak in English.
Why do they not speak in German?
Is this required for the Cockpit Voice Recorder?
In this exchange the pilot is talking through part of the approach with her copilot, who then says
which means "I agree" in German, then immediately afterwards he says
notice how both sound very similar. Further in the flight the copilot, calls