Abstract: A wind-driven electric generator of the downwind type has a wind turbine rotor with oppositely disposed flexible blades attached to the hub of a drive shaft by a flexible spar extending from the hub into hollow portions of the blades. The ends of the spar are attached to intermediate regions of the blades by respective ball joints. Each blade has a root-rib with a stub shaft that is slidably supported in a ball joint mounted on the hub. The blades are pitched to a stall position by a collective pitch mechanism in the absence of proper operating conditions. A nacelle cover of the wind turbine defines an airflow path through the head, and an airflow responsive device inside the nacelle cover controls the collective pitch mechanism to place the blades in a stall position or run position depending upon predetermined airflow conditions. A reverse-cone prevention device limits the ability of the blades to cone reversely.