Occurred on December 13, 2022 Calgary, Alberta, Canadabr br : "This was a video taken by Bernard Guest (me) of Ben Eadie's rubber-powered indoor duration biplane flying in a school gym in Inglewood, Calgary. The airplane is in the process of being trimmed (adjusted) to fly in a small hall for the maximum amount of time. This particular class of airplane must weigh at least 3 grams and the object is to fly for as long as possible using a rubber motor that is wound to more than 2000 turns.