@gullibell... Thank you for jumping in...... I was establishing the principle rather than trying to teach the technique!
@Jagwar... Good point about the Canada Geese. They are substantial birds and would one damage a TR? Who knows? They are however big birds that would probably show up on the video clip and they do tend to fly around in pretty formations, generally only flying by day. If there are significant bird remains on the ground, they will be found by the AAIB.