Atx cabin door opened after takeoff.

Attributes
ACN	86673
Time
Date	198805
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : mkk
State Reference	HI
Altitude	agl bound lower : 350 agl bound upper : 350
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : mkk tower : pou
Operator	common carrier : air taxi
Make Model Name	Small Transport, Low Wing, 2 Recip Eng
Flight Phase	climbout : initial
Flight Plan	VFR
Person 1
Affiliation	company : air taxi
Function	flight crew : single pilot
Qualification	pilot : atp
Experience	flight time last 90 days : 40 flight time total : 5800 flight time type : 40
ASRS Report	86673
Person 2
Function	controller : local
Qualification	controller : non radar
Events
Anomaly	aircraft equipment problem : less severe other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa other other : unspecified
Resolutory Action	other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

Just after takeoff from runway 23 at molokai airport on a flight to maui, at about 350-400' AGL, the upper door of the main cabin entrance door popped either partially or full open (I could not tell from where I was seated) and a corresponding door open caution light came on the advisory panel. There were no control problems with the aircraft, so I kept the airspeed down, configured for landing and advised the passenger to remain calm and that we were circling back around for a landing. After an uneventful landing and taxi and shutdown, I inspected the door for damage. I found no damage and the mechanism for locking the door worked fine, so I relocked the door, took off and flew uneventfully to maui. This is the only aircraft in our fleet that has a locking lever that travels through about a 135 degree arc to extend the door's locking bayonet fittings (all the rest have d-ring handles). The lever does not provide a good means of pulling inward on it while rotating it to the locked position--as does the d-ring handle. Thus, it was either not properly locked (door warning light was checked out and advisory lights pushed to test before takeoff checklist), or a passenger may have moved to another seat and brushed against the lever enough to unlock it. Recommend that the locking lever be changed to the d-ring confign. See drawing of level mechanism (I think the locked/unlocked position are reversed).

Original NASA ASRS Text

Title: ATX CABIN DOOR OPENED AFTER TKOF.

Narrative: JUST AFTER TKOF FROM RWY 23 AT MOLOKAI ARPT ON A FLT TO MAUI, AT ABOUT 350-400' AGL, THE UPPER DOOR OF THE MAIN CABIN ENTRANCE DOOR POPPED EITHER PARTIALLY OR FULL OPEN (I COULD NOT TELL FROM WHERE I WAS SEATED) AND A CORRESPONDING DOOR OPEN CAUTION LIGHT CAME ON THE ADVISORY PANEL. THERE WERE NO CTL PROBS WITH THE ACFT, SO I KEPT THE AIRSPD DOWN, CONFIGURED FOR LNDG AND ADVISED THE PAX TO REMAIN CALM AND THAT WE WERE CIRCLING BACK AROUND FOR A LNDG. AFTER AN UNEVENTFUL LNDG AND TAXI AND SHUTDOWN, I INSPECTED THE DOOR FOR DAMAGE. I FOUND NO DAMAGE AND THE MECHANISM FOR LOCKING THE DOOR WORKED FINE, SO I RELOCKED THE DOOR, TOOK OFF AND FLEW UNEVENTFULLY TO MAUI. THIS IS THE ONLY ACFT IN OUR FLEET THAT HAS A LOCKING LEVER THAT TRAVELS THROUGH ABOUT A 135 DEG ARC TO EXTEND THE DOOR'S LOCKING BAYONET FITTINGS (ALL THE REST HAVE D-RING HANDLES). THE LEVER DOES NOT PROVIDE A GOOD MEANS OF PULLING INWARD ON IT WHILE ROTATING IT TO THE LOCKED POS--AS DOES THE D-RING HANDLE. THUS, IT WAS EITHER NOT PROPERLY LOCKED (DOOR WARNING LIGHT WAS CHKED OUT AND ADVISORY LIGHTS PUSHED TO TEST BEFORE TKOF CHKLIST), OR A PAX MAY HAVE MOVED TO ANOTHER SEAT AND BRUSHED AGAINST THE LEVER ENOUGH TO UNLOCK IT. RECOMMEND THAT THE LOCKING LEVER BE CHANGED TO THE D-RING CONFIGN. SEE DRAWING OF LEVEL MECHANISM (I THINK THE LOCKED/UNLOCKED POS ARE REVERSED).

Data retrieved from NASA's ASRS site as of August 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.