BL8 pilot had the upper door hinge fail in-flight, while doing snap rolls.

Attributes
ACN	516779
Time
Date	200107
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : riu.airport
State Reference	CA
Altitude	msl single value : 4000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	general aviation : personal
Make Model Name	Decathlon
Operating Under FAR Part	Part 91
Flight Phase	cruise : level ground : maintenance
Flight Plan	None
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : commercial pilot : instrument pilot : multi engine
Experience	flight time last 90 days : 20 flight time total : 540 flight time type : 10
ASRS Report	516779
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : detected after the fact
Consequence	other other
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

Door failure during the performance of a right snap roll at 4000 ft MSL. Door did not separate from aircraft, 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 altitude prior to this right snap roll. 90 mph entry speed and throttle per poh. During door failure, upper portion of door went beyond door threshold to impact my right 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 aircraft. Aircraft 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.

Original NASA ASRS Text

Title: 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.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.