The invention relates to a system for opening and closing a window aperture, the system comprising: a moveable window panel; a pulley assembly coupled to the moveable window panel; a counterweight; and a pulley actuation mechanism. The moveable panel is heavier than the counterweight, the latter being attached to a first lateral side of the moveable panel via a first part of the pulley assembly. The pulley actuation mechanism is attached to an opposite lateral side of the moveable panel via a second part of the pulley assembly. The pulley actuation mechanism is switchable between energised and non-energised states based on one or more trigger events, between a closing mode whereby the pulley actuation mechanism retracts the second part of the pulley assembly thus imparting an additional closing force to the moveable panel sufficient to raise the moveable panel; and an opening mode whereby the pulley actuation mechanism is non-energised such that a passive opening force is imparted to the moveable panel by virtue of its weight to lower the moveable panel. A system for controlling a window system based on aircraft detection is also disclosed.

A window, with a hybrid sash counterbalance and assist mechanism, includes a frame having upper and lower sashes slidable within the frame. A sash coupling element extends between the upper and lower sashes. The hybrid sash counterbalance and assist mechanism is coupled with the sash coupling element. The window with the hybrid sash counterbalance and assist mechanism is operable in a sash counterbalance mode and in an independent sash movement mode. In the sash counterbalance mode, movement of the upper or lower sash causes converse movement of the lower or upper sash through the sash coupling element. In the independent sash movement mode, one of the upper and lower sashes is held static while the other of the lower or upper sashes is moved.

A hunting blind with inconspicuously operable windows includes a wall panel; a shelf connected to the wall panel; a window frame in the wall panel above the shelf; a window sash movably received in the window frame; at least one pulley connected to the wall panel; a sash cord disposed about the at least one pulley, the sash cord having a first end and a second end, the first end connected to the window sash; and a counterweight having a top connected to the second end of the sash cord and a bottom extending below the shelf, the counterweight configured to be manually operable from underneath the shelf to move the window sash in the window frame while user movement during operation of the counterweight is substantially concealed from game.