As predicted last week, testing the window with full pressure and cold temperature has blown up the test box with no damage to the window.
The test box was filled with offcuts of blue foam and sealed up. More blue foam was placed on top to hold the dry ice. The dry ice surface temperature was -100F and it froze the window surface down to -70F. Then we pressurised it to above the fuselage design pressure and held that pressure for 30 minutes.
Then we increased the pressure until the box exploded. Watch the 30-second video above.
The explosion was surprisingly violent, destroying the thermometer which was sitting on top of the box. The blue foam inside the box didn’t seem to do much to reduce the explosive force.
The end result is that we reached design temperature and more than twice the design pressure with no effect on the window. This polycarbonate is extremely tough stuff.