Most other videos I have seen have the headsets connected through the camera and headset sockets. I can see you repeating “climb fl100”. Are you dubbing that conversation in later? If so that is an amazing bit of lip synch? What editing software did you use?
Yes, audio recorded separately and edited in later. Editing software is Garmin Verb Edit (to get the GPS information overlaid on video) and Final Cut Pro X.
I’ve just put up a longer post describing my kit and workflow:
Recording In-Flight Video and Audio