Page 19 - Feb 23

“Always leave the cabin win- dows in the non-polarized po- sition whether parked inside or out. Doing so will prolong the life of the polarized panes immensely.”
The polarized windows in a King Air were designed to block sunlight for passengers sitting on the sunny side of the cabin. They are the King Air’s answer to that little sliding shade found on airliners and elsewhere, and they do the trick nicely, but with one major drawback: They are prone to burning out and turning brown.
King Air passenger window assemblies consist of three panes. The exterior pane is not part of the polarization system. The other two panes – a middle, stationary pane and the interior, rotating pane – produce the polarization effect which offers many gradations between clear and maximum darkness. Passengers can choose to control the glare and still see the view if they wish. However, when the inner pane is turned to the darkest position, heat is trapped between it and the stationary pane. This heat buildup burns out the panes.
FEBRUARY 2023
On the Ramp or In the Hangar
I know it is common practice to turn all the rotating panes to the max dark position if your King Air has to stay parked outside for a few days. The idea is to keep the aircraft interior from becoming lava-hot while the aircraft is sitting outside in the blazing sun. Unfortunately, this is exactly what destroys those polarized panes.
For the last 45 years I have been telling King Air owners and pilots: “Never leave the polarized panes in the dark
KING AIR MAGAZINE • 17