I have a ground AC system in my 320. It consists of two wooden wedges with rubber on each side of each wedge, which are attached to ¼” cords which in turn are attached to the canopy rods under the instrument panel. Before engine start, the wedges are placed between the canopy and side fuselage leaving a one inch gap (thereabouts), and the left forearm is then placed on the inside of the canopy to hold it down.

This creates a wonderful cooling airflow through the cockpit after engine start.

Even better when one has a passenger who can place his/her forearm on the canopy on the RHS.

I have not tried to see if it operates successfully in the air, but with advancing age, anything is possible.

Cheers

Dom Crain

Melbourne

Australia

VH-CZJ