What was found
THE DOOR INADVERTENTLY OPENED ON TAKEOFF RIGHT AT ROTATION. THE OPEN DOOR CAUSED THE ANGLE OF ATTACK INDICATOR TO INDICATE AN IMMINENT STALL ON TAKEOFF DESPITE INITIATING A CLIMB AT VY. THE AOA CONTINUED TO INDICATE AN IMMINENT STALL DESPITE SAFE AIR SPEEDS. WE HAVE DETERMINED THAT THE AOA WAS INSTALLED IN ACCORDANCE WITH THE INSTALLATION MANUAL. IT IS MY BELIEF THAT THE INSTALLATION AS REQUIRED BY THE MANUFACTURE CREATES A POTENTIALLY UNSAFE INSTALL. THIS EQUIPMENT AND THE INSTALL WAS APPROVED, BUT AS DESIGNED IT CREATES A DISTRACTION DURING A COMMON FAILURE IN LIGHT AIRCRAFT AND PROVIDES ERRONEOUS INDICATIONS TO THE PILOT DURING A CRITICAL PHASE OF FLIGHT.