AIR TAXI ACFT HAS DOOR OPEN AND DETACH FROM ACFT ON TKOF DAMAGING L ENG.

Narrative

WHILE I WAS FLYING AN SMT FOR A COMMUTER OPERATOR FROM SXP TO KSM ON A FERRY FLT TO RETRIEVE ANOTHER COMPANY PLT AND HAVE OUR MAINT DIRECTOR ASSESS THE DAMAGE TO HIS AIRPLANE. AFTER LDG AT SXP CAME BACK TO THE SMT AT THE BACK; AND DOWNED PLT; MAINT DIRECTOR AND I CLBED IN; AFTER A BRIEF REST. I DID NOT PERFORM A FORMAL WALK AROUND AS COMPANY PROC ONLY CALLS FOR IT ON THE FIRST FLT OF THE DAY. I DID LOOK UP AT THE FRONT OF THE ACFT OUT BOTH SIDES; SO AS TO DETERMINE THAT THE AREA WAS CLR. UPON ENTERING THE COCKPIT; I SAW THAT THE PLT'S DOOR HAD BEEN CLOSED; AND I THOUGHT LATCHED; ALTHOUGH I CAN'T BE CERTAIN. I THEN EXECUTED THE PRESTART CHKLIST. AT THIS POINT I TURNED ON THE RADIOS; CALLED OUT MY INTENTIONS ON 122.9; AND BACKED THE AIRPLANE AROUND ONTO THE RWY. AT THIS POINT I DID MY PRETKOF CHKS; ALTHOUGH I HAVE NO SPECIFIC RECOLLECTION OF CHKING THE DOOR TABS. I TRIMMED THE AILERONS DOWN INTO THE WIND A BIT; AND ADVANCED THE THROTTLES FOR A NORMAL TKOF. UPON ROTATION I IMMEDIATELY YAWED THE AIRPLANE INTO THE WIND SO AS TO TRACK DOWN WHAT REMAINED OF THE RWY; AND BEGAN A GRADUAL L TURN TO CLB OUT OF THE PATTERN AND GO TO ST MARY'S. I HEARD A LOUD BANG COME FROM BEHIND ME IN THE ACFT AND BASED UPON NUMEROUS PERSONAL PRIOR EXPERIENCES OVERSEAS AND THOSE RELATED TO ME BY MY FELLOW PLTS; ASSUMED THAT I HAD LOST A WINDOW OUT OF THE ACFT AND WAS NOT ESPECIALLY CONCERNED AS THIS IS MERELY A MINOR ANNOYANCE; AND HAPPENS OFTEN. IN ACTUALITY; THE L HAND DOOR OF THE AIRPLANE CAME OFF SHORTLY AFTER TKOF; AT APPROX 50 FT AGL (IT IS DESIGNED SO THAT THE DOOR OPENS INTO THE SLIPSTREAM; AND CATCHES THE WIND) AND WENT INTO THE PROP OF THE L HAND ENG. AT ANY RATE; THE L ENG GRADUALLY LOST PWR; AND I FEATHERED IT IMMEDIATELY. WHEN I TURNED MY HEAD TO VISUALLY CHK THAT THE ENG WAS INDEED FEATHERED; I REALIZED THAT IT WAS THE DOOR THAT I HAD LOST; RATHER THAN THE WINDOW. I CONTACTED ANCHORAGE CTR ON 124.00 AND DECLARED AN EMER; AND REQUESTED AN IFR TO BETHEL. THE CTLR GAVE ME A CLRNC UPON REACHING 3000 FT DIRECT TO BETHEL AND OFFERED ASSISTANCE. THE CTR CTLR CLRED ME TO LAND; GAVE ME THE WX. I LANDED ABOUT 1000 FT FROM THE THRESHOLD; TAXIED OFF TO THE RAMP; WAS TOLD BY TWR TO CONTACT FSDO; SHUT DOWN THE AIRPLANE; AT XX30 AND BREATHED A SIGH OF RELIEF. I THEN WAS CONTACTED BY THE FSDO AND THE NTSB; THE DIRECTOR OF OPS; AND THE CHIEF PLT BEFORE REACHING THE TERMINAL. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO. RPTR STATES SITUATION HAS BEEN TERMED AN INCIDENT BY NTSB. COMPANY NOW PAINTS TABS FLUORESCENT ORANGE SO EASIER TO DETECT WHEN CLOSED PROPERLY. ONLY OTHER SOLUTION WOULD BE TO ARRANGE HINGE SO DOOR FLUSH WITH WIND FLOW. WHEN DOOR CAME OFF IT HIT L ENG; DAMAGING ALL PROP BLADES AND SOME DAMAGE INSIDE ENG. HIT L WING STRUT AND CHOPPED INTO THE SKIN. HAD IT GONE 1/16 INCH DEEPER IT WOULD HAVE DONE STRUCTURAL DAMAGE TO STRUT. ALSO DAMAGED STUB WING ON WHEEL. RPTR FEELS LUCKY IT WAS L SIDE AS PROP BLADES FLUNG DOOR DOWNWARD AND AWAY. R SIDE WOULD HAVE FLUNG DOOR UP AND POSSIBLY INTO TAIL SURFACES.