BL8 PLT HAD THE UPPER DOOR HINGE FAIL INFLT; WHILE DOING SNAP ROLLS.

Narrative

DOOR FAILURE DURING THE PERFORMANCE OF A R SNAP ROLL AT 4000 FT MSL. DOOR DID NOT SEPARATE FROM ACFT; BUT REMAINED ATTACHED AT THE REAR HANDLE LOCK MECHANISM AND THE LOWER FORWARD HINGE. FORWARD UPPER HINGE SEPARATED FROM FIBERGLAS DOOR PANEL. A DEFINITE FOLD LINE NOTICEABLE FROM UPPER HINGE TO REAR HANDLE LOCK MECHANISM. THIS SEEMED TO INDICATE THAT THE UPPER FORWARD LATCH AND THE TOP LATCH MECHANISMS RELEASED DURING THE MANEUVER. HAD PERFORMED 2 LEFT SNAP ROLLS WITHOUT INCIDENT AND NO LOSS OF ALT PRIOR TO THIS R SNAP ROLL. 90 MPH ENTRY SPD AND THROTTLE PER POH. DURING DOOR FAILURE; UPPER PORTION OF DOOR WENT BEYOND DOOR THRESHOLD TO IMPACT MY R EAR AND JAW. RESTRAINT MECHANISM EXTREMELY TIGHT NEGATING POSSIBILITY OF HEAD MOVEMENT BEYOND DOOR THRESHOLD. NO DAMAGE TO DOOR THRESHOLD OR ANY OTHER PORTION OF ACFT. ACFT WAS LANDED SAFELY; WITHOUT INCIDENT. SUGGEST THAT THE LATCH MECHANISMS FOR THE DOOR BE CHANGED TO PROVIDE MORE SECURITY; LESS CHANCE OF UNPLANNED FOR RELEASE DURING MANEUVERS SUCH AS SNAP ROLLS; WHICH ARE EXTREMELY VIOLENT.