CE207 PLT GOES OFF END OF ICY RWY AT ZZZ.

Narrative

WHEN LNDG AT ZZZ THE AIRPLANE WENT OFF THE END OF THE RWY. ZZZ IS A 1650 FT LONG GRAVEL STRIP IN SOUTH WESTERN ZZZ. AT THE TIME OF LNDG; THE RWY WAS COVERED IN A LAYER OF SNOW THAT HAD MELTED AND REFROZEN. THE RWY WAS JUST A SMOOTH LAYER OF ICE; IT HAD NOT BEEN ROUGHENED WITH THE GRATER OR HAD GRAVEL SPREAD ON IT. WHILE FLYING TO ZZZ MY GND SPD WAS SLIGHTLY HIGHER THAN NORMAL; CAUSING ME TO BELIEVE THAT THE WIND WAS OUT OF THE S. BASED ON THIS ASSUMPTION I ENTERED A DOWNWIND FOR RWY 20. I FLEW A NORMAL PATTERN FOR RWY 20; BUT WHEN I TURNED FINAL; I NOTICED MY GND SPD WAS ABOUT 5 KTS HIGHER THAN MY AIRSPD. I DECIDED TO CONTINUE THE APCH; BELIEVING THAT THE TAILWIND WAS MINIMAL AND WOULD NOT DRASTICALLY INCREASE THE LNDG DISTANCE. THE FLARE AND LNDG WERE PERFORMED AS NORMAL; IMMEDIATELY UPON TOUCHDOWN THE FLAPS WERE RETRACTED AND HVY BRAKING WAS APPLIED. DUE TO THE RWY CONDITIONS; THE PLANE DID NOT SLOW DOWN AS FAST AS I THOUGHT IT WOULD. WHEN I REACHED THE FAR END OF THE RWY THE PLANE WAS MOVING LESS THAN 15 MPH; GOING THROUGH THE TURN AROUND AREA AND OFF THE EMBANKMENT AT THE END. THE SNOW AFTER THE EMBANKMENT WAS 6-12 INCHES DEEP AND CRUSTED; CAUSING THE PLANE TO STOP QUICKLY. THE NOSEWHEEL BROKE THROUGH THE CRUST AND CAME OFF THE AIRPLANE. THE LOWER PROP BLADES WERE BURIED IN THE SNOW; STOPPING THE ENG. I TURNED OFF THE MASTER AND MAGNETOS AND THEN WE EXITED THE AIRPLANE. THE MAJOR CAUSE OF THIS INCIDENT WAS MY DECISION TO LAND WITH A TAILWIND; THE MAIN CONTRIBUTING FACTOR WAS THE ICY RWY. IF I HAD CHOSEN TO LAND IN THE OTHER DIRECTION WHEN I REALIZED THERE WAS A TAILWIND THIS WOULD NOT HAVE HAPPENED.