Loud popping from windows C550

[ppppilot]

On the CRJ200 it was very usual. Engineers told me it was due the crystal was not totally fixed to the frame. It was that way to permit different expansion of the cell and the crystal due to presurization. All that noises are frightening, but it doesn’t mean something bad must happen.
The fact is I flew Crj more than 4 years and during that time I suffered 2 windows crashed in flight. Cockpit windows are made of several layers. The CRJ200 windshields are 3. I don’t remember if side windows were 2 layers. Interior and exterior are crystal. The intermediate it is a kind of polycarbonate.
First crash was the interior layer of the right side window. Flying FL360, right before beginning of the descent for the APP. It sounded like a little explosion, followed by a straight cut from one corner to the opposite. I began to descend and during the descent small cuts were produced at small intervals from the main cut in random directions. In a few minutes little pieces of crystal fell down over the first officer who left his seat for the rest of the app. At the ldg the crystal stopped to crash.
The second was close to Zurich at FL350. The explosion was bigger and the interior layer of the left front window was totally broken in small pieces. It was impossible to see through. I initiated a soft descent while deviating to LYS. At our arrival I took a couple of pictures, sent them to my company and the next day I had a ferry authorization and a brief analysis from Bombardier to fly back to Spain. I made the fly depressurized at 7000ft 180 Knt without incidences.
Since then I am always looking at the different types of window. I have realized that they are usually flat crystal. But there are small airplanes with big windows that follow the curve of the cell. If you look trough that type of windows you will notice that the vision is deformed at some points indicating that this is not it natural shape and they have been forced to it. These are dangerous to my opinion. I believe if windows are flat or almost support better the cell expansion. At least the expansion is more lineal and it doesn’t produce that crack sound. The Fokker 50 has a nosy crack perfectly audible all over the airplane, produced by the big pax door when it adjusts to the expanded frame.
Good luck.