Issued: April 2017
ATA 56 – Window Electronic Shades – Cold Temperatures
Serial Numbers LJ-2137 and after; BY-207, BY-239, BY-250 and after; FL-954, FL-972, FL-1031 and after.
As part of the 2015 block point Fusion Avionics upgrade, Textron Aviation also upgraded the cabin windows with a new electronic dimmable window. This window uses electric current to charge an emulsion trapped between the panes to become dark shaded and/or opaque to block sunlight.
On the ground this helps keep the cabin cooler and protect the interior from ultraviolet rays; when the power is off the window defaults to dark. Condition Reports from operators have made us aware of the fact that prolonged exposure to subzero temperature can slow down the process to darken or clear the window especially on the shaded side of the cabin at altitude. While on the ground, you can expect it to change in a few seconds, but at altitude and subzero conditions you can expect it to take a couple of minutes. On the exit windows, especially, you may encounter a waterfall effect as it slowly darkens. Engineering is aware of this issue and is working with the supplier for a solution. You can expect this condition to improve on descent and should produce no lasting effects to the window.
On another note for the windows, you may experience a rainbow effect when looking out the windows in certain conditions or while taking pictures. This is caused by the emulsion along with the polycarbonate dust pane; this is also being looked at for possible improvement.
Another issue is not being able to clear windows before engine start because of voltage drop which can cause a flickering issue. This issue has been solved and is in the certification process now.
The above information is abbreviated for space purposes. For the entire communication, go to www.txtavsupport.com.