ACFT DAMAGED AFTER EXPERIENCING A RWY EXCURSION.

Narrative

I WAS FLYING TO THIS UNCTLED GRASS ARPT TO VISIT RELATIVES LIVING NEARBY. MY FLT HAD BEEN DELAYED BECAUSE OF UNRELATED MECHANICAL DIFFICULTIES THAT WERE CORRECTED BEFORE DEP. BECAUSE OF THE DELAY I DID NOT ARRIVE AT THE FIELD UNTIL DUSK. I HAD NEVER LANDED AT THIS ARPT AT DUSK. AS SUCH; I MADE MY APCH SLIGHTLY FASTER AND HIGHER THAN NORMAL. WHEN MY MAIN GEAR TOUCHED DOWN; I PLACED THE FLAP SELECTOR IN THE RETRACT POS BECAUSE I FELT I NEEDED THE ADDITIONAL BRAKING AUTH THAT WOULD GIVE ME. THE ACFT DID NOT FEEL LIKE IT WAS BRAKING NORMALLY. AS I BRAKED IT TENDED TO FISHTAIL SOMEWHAT. I ASSUMED THIS WAS DUE TO SOME MOISTURE ON THE GRASS. WHEN I WAS APPROX 300 FT FROM THE END OF THE RWY (TOTAL LENGTH 2600 FT) I BECAME CONCERNED THAT I WAS NOT GOING TO BE ABLE TO STOP THE ACFT IN TIME. I CONTINUED TO BRAKE HARD. MY ACFT WENT INTO THE DITCH AT THE END OF THE RWY WHILE I WAS STILL TRAVELING APPROX 10 MPH. THE NOSEWHEEL FOLDED INTO THE WELL AND THE PROP WAS SLIGHTLY DAMAGED. NO STRUCTURAL DAMAGE WAS DONE TO THE ACFT NOR WAS THERE ANY PERSONAL INJURY. AFTER THE ACFT CAME TO A STOP; I DISCOVERED THAT MY FLAPS WERE STILL IN THE FULL EXTENDED POS. I RECHKED THE POS OF THE FLAP CTL AND FOUND IT TO BE IN THE RETRACT POS WHERE I HAD PLACED IT. I THEN CHKED THE CIRCUIT BREAKERS AND FOUND THAT THE FLAP BREAKER HAD POPPED; APPARENTLY AT THE TIME THAT I EXTENDED THE FLAPS. I ALSO FOUND OUT THAT THE GRASS HAD JUST BEEN MOWED. I BELIEVE 3 THINGS CONTRIBUTED TO THIS INCIDENT. FIRST; BECAUSE OF MY UNFAMILIARITY WITH THE FIELD IN DUSK CONDITIONS; I MADE AN APCH FASTER THAN NORMAL; AND TOO FAST TO ALLOW A SUFFICIENT MARGIN OF SAFETY. SECOND; BECAUSE MY FLAPS DID NOT RETRACT; I HAD MUCH LESS BRAKING AUTH THAN NORMAL. THIRD; BECAUSE THE GRASS HAD JUST BEEN MOWED; TRACTION WAS REDUCED. I BELIEVE THIS INCIDENT COULD HAVE BEEN AVOIDED BY BETTER ADHERENCE BY ME TO SHORT FIELD LNDG TECHNIQUES; AND A PRE-LNDG COCKPIT CHK OF CIRCUIT BREAKERS.