PLT OF SMA PVT ACFT HAD AN NMAC WITH ANOTHER ACFT ON AN EMER LNDG DUE TO ENG FAILURE;

Narrative

AFTER MAKING THE VOR A APCH AT 29D; ACFT WAS TURNED UPWIND IN TFC PATTERN AT APPROX 600 FT AGL AS SPECIFIED IN INST APCH PROCS. DURING UPWIND AND XWIND; ACFT WAS TAKEN UP TO TFC PATTERN ALT AND THE REST OF APCH MADE IN VFR CONDITIONS. THE INST APCH WAS 'UNDER THE HOOD' WITH A SAFETY PLT AND 1 ADDITIONAL PAX. ALL POS RPTS WERE MADE IN PATTERN; ON UNICOM 122.70 MHZ. NO TFC WAS NOTED VISUALLY OR BY RADIO DURING THE APCH. AFTER LNDG; ACFT WAS PULLED ONTO SHORT TAXIWAY ABOUT 3000 FT FROM APCH END AND 'CLEANED' UP. OUT OF THE CORNER OF MY EYE; I NOTED ANOTHER ACFT OFF THE SIDE OF THE RWY IN THE MUD AND GRASS. AS I GOT OUT OF MY AIRPLANE; SEVERAL PEOPLE CAME OUT OF THE ARPT OFFICE BUILDING AND INFORMED ME THAT ANOTHER AIRPLANE HAD ALMOST HIT ME FROM BEHIND. A STUDENT PLT WAS FLYING THE OTHER ACFT. HE STATED THAT HIS PLANE HAD LOST PWR (PROBABLY DUE TO CARB ICING). THE STUDENT WAS ON A SOLO XCOUNTRY AND WAS TRYING TO REACH THE NEAREST ARPT. A CHK OF HIS PLANE SHOWED HE WAS ON 122.80 (NOT LCL FREQ). STUDENT'S DESCRIPTION INDICATED HE CAME IN HIGH AND FAST. HE APPARENTLY DID NOT USE PROPER UNICOM FREQ; AND APCHED ARPT FROM R BASE POS. NEITHER MYSELF; SAFETY PLT; NOR PAX OBSERVED STUDENT'S PLANE. OBSERVERS ON GND ALSO STATED THAT THEY HEARD NO COMS ON UNICOM FREQ FROM STUDENT'S ACFT.