AN ACR; WITHOUT AN OPERATING TAXI LIGHT; MISSES A TXWY AND THE L MAIN GEAR LEAVES THE HARD SURFACE AND THE L PROP STRIKES A PLASTIC CONE -- NO DAMAGE.

Narrative

I AM A NEWLY RATED CAPT AT MY COMMUTER AIRLINE. PRIOR TO BEING RATED AS A CAPT I HAD NEVER BEFORE FLOWN THE SA227 METROLINER; HOWEVER; I DO NOT BELIEVE THIS HAD SIGNIFICANT EFFECT ON THE OUTCOME OF THE INCIDENT. AT THE TIME OF THE INCIDENT; I WAS OCCUPYING THE L COCKPIT SEAT OF THE ACFT WHILE UNDERGOING IOE WITH A TRAINING CAPT IN THE R SEAT. WE WERE COMPLETING THE LAST OF 4 LEGS OF OUR TRIP. WE LANDED ON RWY 32 AT IMPERIAL; CA; AND EXITED THE RWY TO THE E TXWY NORMALLY. ONCE ESTABLISHED ON THE TXWY WE NOTICED THAT OUR SINGLE NOSE GEAR MOUNTED TAXI LIGHT WAS INOP. ALTHOUGH THE ENVIRONMENT WAS EXTREMELY DARK; VISIBILITY ALONG THE TXWY WAS ADEQUATE USING THE EXISTING BLUE EDGE LIGHTS. HOWEVER; THE TXWY LIGHTS DID NOT EXTEND ALL THE WAY TO THE ENTRANCE TO THE AIRLINE TERMINAL RAMP; AND IT WAS DIFFICULT TO SEE THAT ENTRANCE; ESPECIALLY WITHOUT ADEQUATE ACFT LIGHTING. COMPOUNDING THE PROB WAS THE GLARE FROM THE LIGHTS AT THE TERMINAL WHICH EFFECTIVELY WASHED OUT ANY ADEQUATE DEFINITION OF THE GND SURFACE. UPON APCHING THE TERMINAL RAMP I SAID TO THE TRAINING CAPT; 'SHOULD I TURN IN HERE?' HE RESPONDED WITH WHAT I UNDERSTOOD TO BE AN AFFIRMATIVE SO I BEGAN MY L TURN. 2-3 SECONDS LATER I FELT WHAT I THOUGHT WAS THE L MAIN GEAR MOVING THROUGH SOMETHING SOFT. WE HAD ENTERED THE DIRT WITH THE L MAIN GEAR ABOUT 2 FT OUT FROM THE EDGE OF THE PAVEMENT. AFTER TRAVELING ABOUT 20 FT IN THIS MANNER; IN A STRAIGHT LINE; THE ACFT RETURNED TO THE PAVEMENT. LATER INSPECTION OF THE AREA ALSO REVEALED THE L PROP HAD STRUCK A LIGHTWEIGHT PLASTIC REFLECTIVE MARKER; ABOUT 1 FT IN HEIGHT; EMBEDDED IN THE DIRT NEAR THE PAVEMENT. THE MARKER COULD NOT BE SEEN BECAUSE THERE WAS NO LIGHT TO ILLUMINATE IT; NOR WERE THERE ANY COCKPIT INDICATIONS AT THE MOMENT THE PROP STRUCK THE MARKER TO INDICATE THIS HAD TAKEN PLACE. COMPANY MAINT SUBSEQUENTLY INSPECTED THE ACFT; INCLUDING THE PROP; DID ENG RUNS AND FOUND NO DAMAGE OF ANY KIND. IMPERIAL COUNTY ARPT AUTHS WERE NOTIFIED AND NO ACTION WAS TAKEN AGAINST ME OR MY COMPANY. I BELIEVE I RELIED TOO MUCH ON THE TRAINING CAPT'S ABILITY TO CORRECT MY MISTAKES AND NOT ENOUGH ON MY OWN JUDGEMENT. ALTHOUGH NOT RECOMMENDED FOR USE ON THE GND; HAD I TURNED ON THE LNDG LIGHTS MOMENTARILY THIS MAY NOT HAVE OCCURRED.