What was found
(CAN) WHILE FLYING STRAIGHT AND LEVEL AT AN INDICATED AIRSPEED OF 87 KNOTS, THE BUBBLE WINDOW FLEW OUT OF THE FWD RT DOOR. THE PILOT SLOWED THE ACFT TO 70 KNOTS AND LANDED WITHOUT FURTHER INCIDENT. DAMAGE WAS FOUND ON THE REAR MIDDLE PORTION OF THE DOOR AT THE MIDDLE LATCH AREA. THE NATURE OF THE DAMAGE IS INDICATIVE OF THE UPPER HALF OF THE DOOR BEING SUBJECTED TO SEVERE BENDING LOADS, LIKELY CAUSED BY THE SUCTION EFFECT OF THE BUBBLE WINDOW. THIS WOULD NOT BE POSSIBLE IF THE UPPER DOOR LATCH WAS SECURED PROPERLY IN ITS RECESS. IT IS SUSPECTED THAT THE UPPER DOOR LATCH WAS NOT CLOSED PROPERLY AND ALLOWED THE WIND SUCTION ON THE BUBBLE WINDOW TO BEND THE UPPER HALF OF THE DOOR OUTWARDS UNTIL IT WAS DEFORMED ENOUGH TO LET THE WINDOW COME FREE OF THE DOOR AND FALL OFF. THE BUBBLE WINDOW INSTALLATION WAS UNDER STC SH05-13.