A rubber band free flight De Havilland Tiger Moth kit converted to radio controlled electric power...and it flew so well. This 18 inch / 460mm wingspan kit is available from Vintage Model Company (https://www.vintagemodelcompany.com/tiger-moth.html) and takes very little time to build apparently. With modern micro servos, small brushless electric speed controllers and motors the conversion isn't too challenging either.

Lovely!!