PLT OF AN SMA TWIN ENG ACFT GOT STUCK IN THE MUD AFTER INADVERTENTLY RUNNING OFF THE TXWY AT NIGHT RESULTING IN DAMAGE TO THE R PROP.

Narrative

I STARTED TO TAXI ON THE OUTER TXWY TO THE RWY. THERE WAS NO OTHER ACTIVITY ON THE ARPT. THE TXWY LIGHTS WERE INOP DUE TO RECENT CONSTRUCTION. THERE WERE NO REFLECTIVE MARKERS OR OTHER VISUAL INDICATORS ALONG THE EDGE OF THE TXWY THAT COULD HAVE AIDED ME. I USED MY LNDG LIGHTS TO TAXI AND I INADVERTENTLY TAXIED OFF THE TXWY. I ADDED PWR TO KEEP UP MY MOMENTUM AS I ATTEMPTED TO RETURN TO THE TXWY. BUT THEN THE R MAIN GEAR SUNK INTO THE DITCH. THE RECENT CONSTRUCTION INCLUDED A NEW DITCH FOR WORK ON THE TXWY LIGHTS. THE DITCH WAS FILLED IN BUT THE CLAY WAS VERY SOFT AND SATURATED BECAUSE OF RECENT RAIN. AFTER SINKING INTO THE DITCH; I IMMEDIATELY SHUT DOWN BOTH ENGS AND ALL SYS. THE SINKING OF THE R GEAR INTO THE DITCH CAUSED THE R PROP TO STRIKE THE MUD. I WALKED BACK TO THE FBO BUILDING AND CALLED THE OWNER OF THE ACFT FROM THE OUTSIDE PAY PHONE. THE OWNER OF THE ACFT PLUS THE OWNER OF THE FBO AND A MECH ARRIVED TO TRY TO GET OUT THE ACFT. A CRANE WAS USED TO LIFT OUT THE PLANE AND PLACE IT ON THE TXWY. THEN THE PLANE WAS TOWED TO THE HANGAR WITH A TUG.