An Aces High film is not a video. It's a debugging dump that can be played back. However, it needs Aces High to be installed in order to play back (and if pieces of it have been replaced [such as what's up with the sound system right now] or are missing [like the terrain file], it won't play back exactly right).
To create actual video for a site like YouTube, you have to use the Film Viewer to export to AVI. You play back the file and WYSIWYG, so you have to play with the views as it exports and any dropped frames will show in the resulting AVI. In short, it's a pain.