Cockpit Window Cracked

One of our BBJ aircraft came back with number 2 cockpit window cracked. No 2 window is the only window that can be opened, it slide backward. This is very dangerous situation where it might lead to rapid decompression however by knowing the construction of the window itself, we can be assured that the safety is not tolerated.

This window is a laminated assembly of layers of glass and vinyl or urethane. The structural inner glass pane carries pressure loads. The vinyl interlayer is structural for bird impact resistance and fail-safe pressure loads.

The current window manufactured by PPG has these layers: an non-structural outer glass pane, a non-structural urethane interlayer, a structural vinyl interlayer, a non-structural urethane interlayer and an structural inner glass pane.

A conductive film is located on the inner surface of the outer glass pane, which is a part of the window heat system that supplies the anti-fog and the anti-ice function.

Rest of the cockpit window have almost the same construction. The passanger window however in stuuctured in layers as well minus the heating element.

Few months earlier one of our Gulfstream had a similar incident where the number 1 cockpit window cracked during flight, from the sign of arcing at the top left corner of the window, overheated is the probable caused for the damaged.


  1. Anonymous said...

    nice info..but i need to explore some more, what makes the heating element overheated? and how the rectification carried out?
    -aviation trainee.

  2. Helmis said...

    It could be because of the aging window, after few years in operation, they unable to stand the effect of heat and pressurisation. Thanks to the triple layer design that is fail safe.