AN SMA ENG SWALLOWED A VALVE.

Narrative

OVER RICHMOND THE ENG STARTED MAKING SERIOUS SOUNDS AND RUNNING ROUGH. I REQUESTED VECTORS TO THE NEAREST ARPT FOR AN EMER LNDG AND WE SWITCHED FUEL TANKS; MAGNETOS; MIXTURE; PWR; ETC; BUT THE ENG WAS SOUNDING WORSE. WE WERE AT BEST GLIDE BUT LOSING 500 FPM. THE PLT ASKED ME WHAT TO DO. BAY APCH TOLD ME IT WAS 10 MI TO ALAMEDA NAS WHICH INVOLVED FLYING OVER A POPULATED AREA. I SAW A FIELD AND TOOK THE CTLS. BY THIS TIME WE WERE AT 1800 FT. I SAW A RADIO CTLED STRIP WITH 2 RWYS AND SAID I WOULD LAND IT THERE. AT 1000 FT AN ANIMAL WALKED OUT TO THE STRIP AND STOOD AT THE INTXN OF BOTH RWYS. A CIRCLED OVERHEAD AND IT DID NOT MOVE. IT WAS A HORSE. BY THIS TIME I WAS TOO LOW TO SET UP A PROPER APCH SO I CONTINUED TO CIRCLE. WHEN I GOT TO 100 FT I SLOWED TO 80 MPH AND LOWERED GEAR; AND FINISHED EMER CHKLIST. I GOT CLOSE TO THE GND AND ADDED 10 DEGS OF FLAPS AND FLARED. WE HIT A SMALL DIRT MOUND AND SOME BUSHES AND THEN HIT MUD. THE GEAR COLLAPSED; THE PROP WAS BENT BUT NO ONE WAS INJURED. THE LNDG WAS OK. PART OF THE FIELD WAS MUD FROM THE RECENT RAINS. WHEN WE WERE AT 200 FT; I ALSO NOTICED THAT MY SEAT BELT SHOULDER HARNESS WAS NOT ON AND I HAD THE BACK SEAT PAX HAND IT TO ME. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATES THAT THE ACFT WAS A PA 28-200R. THE ENG HAS NOT YET BEEN TORN DOWN; BUT APPARENTLY IT 'SUCKED A VALVE' AS DETERMINED BY LOOKING THROUGH A SPARK PLUG HOLE. THERE WERE NO INJURIES AND NO REPERCUSSIONS FROM THE FAA. THE ACFT COULD NOT MAKE CCR. THE LAND WHERE THIS INCIDENT HAPPENED IS VERY ROUGH WITH WATER AND LARGE OIL REFINERIES TAKING UP ALL OF THE AVAILABLE FLAT AREA.