In Case You Missed It
Aero ‘lectrics
Columnist Jim Weir has completed his solar-powered battery charger, and it works! It may not be the fastest charger, but it is certainly up to the task of keeping a battery topped off, even in winter.
Wind Tunnel
Stall flutter is the result of the elastic axis of a wings surface being aft of the aerodynamic center, resulting in instability. A vicious cycle of lift, twist, stall and lift may ensue.