Beech 1900D cabin door came ajar during final approach.

Attributes
ACN	505821
Time
Date	200103
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : ric.airport
State Reference	VA
Altitude	msl single value : 3000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : lou.tower
Operator	common carrier : air taxi
Make Model Name	Beech 1900
Operating Under FAR Part	Part 135
Flight Phase	descent : approach
Route In Use	approach : straight in
Flight Plan	IFR
Person 1
Affiliation	company : air taxi
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : commercial pilot : cfi
Experience	flight time last 90 days : 72.0 flight time total : 1230 flight time type : 72.2
ASRS Report	505821
Person 2
Affiliation	company : air taxi
Function	flight crew : captain oversight : pic
Events
Anomaly	aircraft equipment problem : critical cabin event other
Independent Detector	other flight crewa other flight crewb
Resolutory Action	none taken : insufficient time none taken : unable
Consequence	other
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

While on final approach to richmond, va, we had the cabin door open. Prior to taxi, carefully closed and inspected the door, its j-hook, the handle, the annunciator was extinguished, and the cam-locks for alignment and everything was in order. We climbed to 16000 ft MSL and pressurized normally, then while descending through 3000 ft MSL on final approach to ric, the cabin door opened. We landed the airplane, taxied in to the gate and exited the aircraft. My opinion on the cause is of the improper locking of the door would be the various failures of microswitches and the j-hook appeared to be locked but after maintenance took a close look, the j-hook was not, even though it appeared to be locked. My recommendation would be to make a simpler door locking system. There are too many places where a pilot can make an error or as seen in this case, check everything but have a door open due to a j-hook not being properly adjusted.

Original NASA ASRS Text

Title: BEECH 1900D CABIN DOOR CAME AJAR DURING FINAL APCH.

Narrative: WHILE ON FINAL APCH TO RICHMOND, VA, WE HAD THE CABIN DOOR OPEN. PRIOR TO TAXI, CAREFULLY CLOSED AND INSPECTED THE DOOR, ITS J-HOOK, THE HANDLE, THE ANNUNCIATOR WAS EXTINGUISHED, AND THE CAM-LOCKS FOR ALIGNMENT AND EVERYTHING WAS IN ORDER. WE CLBED TO 16000 FT MSL AND PRESSURIZED NORMALLY, THEN WHILE DSNDING THROUGH 3000 FT MSL ON FINAL APCH TO RIC, THE CABIN DOOR OPENED. WE LANDED THE AIRPLANE, TAXIED IN TO THE GATE AND EXITED THE ACFT. MY OPINION ON THE CAUSE IS OF THE IMPROPER LOCKING OF THE DOOR WOULD BE THE VARIOUS FAILURES OF MICROSWITCHES AND THE J-HOOK APPEARED TO BE LOCKED BUT AFTER MAINT TOOK A CLOSE LOOK, THE J-HOOK WAS NOT, EVEN THOUGH IT APPEARED TO BE LOCKED. MY RECOMMENDATION WOULD BE TO MAKE A SIMPLER DOOR LOCKING SYS. THERE ARE TOO MANY PLACES WHERE A PLT CAN MAKE AN ERROR OR AS SEEN IN THIS CASE, CHK EVERYTHING BUT HAVE A DOOR OPEN DUE TO A J-HOOK NOT BEING PROPERLY ADJUSTED.

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.