ACFT WING LIGHTS AND TAXI LIGHT OUT OF SERVICE; RESULTING IN TAXI OFF TXWY AND STRIKING CULVERT.

Narrative

THE FLT WAS CONDUCTED WITH BOTH THE TAXI AND LNDG LIGHTS BURNED OUT. THE TKOF FROM MWC AT DUSK; THE FLT AND THE LNDG AT MIC WERE UNEVENTFUL. I LANDED ON RWY 13L AT XA20 AND CONTINUED TO THE END. FROM THE END OF RWY 13L I TURNED LEFT ONTO THE E PERIMETER TXWY. I FOLLOWED THE TXWY THROUGH THE LEFT TURN OF THE NE CORNER AND BACK TO THE 3-TXWY Y INTXN. (THE E PERIMETER TXWY ENDS HERE AND THE TXWYS RUNNING PARALLEL AND ACROSS THE BASE OF RWY 23R AND L FORK TO THE RIGHT AND LEFT.) IN THE DARK; I DID NOT SEE THE FORK IN TIME TO MAKE A NORMAL TURN SO I STOPPED THE ACFT. AT THIS PONT THE ACFT WAS AT THE EDGE/END OF THE TXWY FACING 260 DEGS WITH TXWYS TO THE RIGHT AND LEFT AT 320 DEGS AND 230 DEGS. I WAS UNABLE TO TURN THE ACFT TO THE RIGHT OR LEFT FROM THIS LOCATION BECAUSE MIC HAS REFLECTIVE MARKERS SET BACK FROM THE EDGE OF THE TXWYS AT INTXNS. I WAS SITUATED WITH THE MARKERS 4-5' AHEAD AND TO MY RIGHT AND LEFT. I DEEMED THAT EVEN A HARD TURN WOULD BRING THE OUTSIDE MAIN WHEEL INTO A MARKER. HOWEVER; THERE WAS SUFFICIENT ROOM BTWN THE MARKERS TO TAXI THE ACFT THROUGH TO THE TURF RWY 23L. I DECIDED TO TAXI THE ACFT AHEAD AND PIVOT TO THE RIGHT AROUND THE MARKER TO MY RIGHT AND BACK ONTO THE TXWY HDG 320 DEGS (ACROSS THE BASE OF RWY 23R & L). I EASED THE ACFT FORWARD SLOWLY MAKING SURE THAT THE WING STRUT WAS CLEAR OF THE MARKER. WHEN I COULD SEE THE MARKER BEHIND THE STRUT; I ADDED PWR AND APPLIED THE RIGHT BRAKE TO PIVOT AROUND IT. THE ACFT SWUNG THROUGH 60 DEGS OF THE TURN AND THEN PITCHED DOWN VIOLENTLY AND THE ENG STOPPED. I KILLED THE MASTER AND MAGS; GOT THE PAS OUT OF THE ACFT AND EXAMINED THE PROB. I DISCOVERED THAT THERE WAS AN 18' CULVERT BEHIND THE MARKER I HAD CHOSE TO TURN AROUND. THE CULVERT RUNS PARALLEL TO THE TXWY I ARRIVED ON (320 DEGS). AS THE NOSE WHEEL CAME EVEN WITH THE MARKER IT DROPPED INTO THE CULVERT; BRINGING THE PROP INTO CONTACT WITH THE GND ON THE OTHER SIDE OF THE CULVERT. DAMAGE TO THE ACFT CONSISTED OF A BROKEN NOSE WHEEL PANT AND A BENT PROP WITH POSSIBLE ENG DAMAGE FROM THE SUDDEN FORCED STOP.