Without getting into detail of what we use them for, we do fly often without doors. We have a nose mounted FLIR that weighs about 100lbs. offset to the left of the nose centerline. Looking today, the high time airframe is 1097 hours, still a youngster. Some with the debonding and crack issues have less than 130 hours. The aircraft that came apart has less than 780 hours. All aircraft were manufactured in the Marignane plant. We routinely fly at 5000-5200 lbs. We have the Arriel 2B engine (550 C3). We do touchdown autos when training.