C172 ON SHORT FINAL HAS CLOSE ENCOUNTER WITH A BELLANCA TAKING THE RWY FOR DEPARTURE. NO CTAF/UNICOM CALLS WERE HEARD BY THE REPORTER.

Narrative

I TERMINATED FLT FOLLOWING WITH ALBANY APCH AS WE NEARED THE VILLAGE OF CHESHIRE; MA; AND AFTER LISTENING TO THE ASOS AT PSF; I ANNOUNCED MY POS OVER ONOTA LAKE ON THE PITTSFIELD UNICOM FREQ (122.7) AND DESCRIBED MY INTENTION TO ENTER A R DOWNWIND FOR RWY 32 PITTSFIELD. I FLEW A STANDARD RECTANGULAR PATTERN IN THE PRESCRIBED DIRECTION (R TURNS) AND AT THE PRESCRIBED ALT (2200 FT). I ANNOUNCED MY POS ON EVERY LEG OF THE PATTERN AND I DISTINCTLY REMEMBER ANNOUNCING THAT I WAS ON A 1 MI FINAL FOR RWY 32 PITTSFIELD. THROUGHOUT OUR TRIP AROUND THE PATTERN; WE WERE AWARE OF AN ACFT BEHIND THE HOLD LINE ON THE TXWY LEADING TO THE DEP END OF RWY 32. MY WIFE; A STUDENT PLT; AND I DISCUSSED THE ACFT AND SHE SAID SHE WOULD KEEP AN EYE ON IT -- AS IS CUSTOMARY FOR US IN SUCH SITUATIONS. IT APPEARED THAT THE ACFT IN QUESTION WAS PLANNING TO WAIT THERE UNTIL WE COMPLETED OUR LNDG. THE VIEW OF THE ACFT THROUGHOUT THE FINAL APCH WAS UNOBSTRUCTED. WE HAD STROBES; BEACON; RUNNING LIGHTS; AND LNDG LIGHTS ON. AS WE APCHED; WITHIN APPROX 300 FT OF THE THRESHOLD; THE ACFT SUDDENLY ROLLED ONTO THE RWY AND TURNED INTO TKOF POS. I COULD NOT BE SURE AT THAT POINT IF HE CONTINUED HIS TKOF ROLL; BUT AS I PASSED OVER THE ACFT; I IMMEDIATELY INITIATED A GAR; FLYING JUST TO THE L OF AND PARALLEL TO THE RWY AND CLBING TO PATTERN ALT. I WOULD ESTIMATE THAT I WAS ABOUT 200 FT AGL WHEN I PASSED OVER THE ACFT. NOT WORRYING ABOUT PROPER RADIO TERMINOLOGY AT THAT POINT; I YELLED INTO THE RADIO 'YOU ROLLED OUT RIGHT IN FRONT OF ME --STAY WHERE YOU ARE!' LET ME EMPHASIZE THAT AT NO TIME DID I HEAR ANY RADIO XMISSION ON 122.7 FROM THAT ACFT UP TO THAT POINT. ABOUT THE TIME I REACHED THE DEP END OF THE 3500 FT RWY (RWY 32) AND BEFORE I REACHED PATTERN ALT; I HEARD A RADIO CALL SAYING THE ACFT WAS RIGHT BELOW US. AT THE SAME TIME MY WIFE YELLED OUT THE SAME THING. MY WIFE AND I BOTH REMEMBER HEARING AN UNIDENTED CALL FROM A VOICE SAYING 'ARE YOU ON FREQ? WE ARE RIGHT BELOW YOU.' IT SEEMS REASONABLE TO ASSUME THIS XMISSION CAME FROM THE INTRUDER; BUT I COULD GET NO REPLY TO MY REPEATED RESPONSE. IF THAT CALL CAME FROM THE INTRUDER; IT WAS THE ONLY XMISSION WE EVER HEARD FROM THAT ACFT DURING THE ENTIRE EPISODE. JUST AT THAT MOMENT; THE INTRUDER SUDDENLY APPEARED IN A STEEP R TURN NO MORE THAN 150 FT OFF OUR R WING AND ABOUT 150 FT BELOW US. CLRLY; HE HAD CONTINUED HIS TKOF ROLL AND; BEING A MUCH FASTER ACFT; HAD OVERTAKEN US. I DID AN EXTENDED 'UPWIND' TRYING TO PUT SOME DISTANCE BTWN THE 2 PLANES. AFTER TURNING DOWNWIND; WE WERE ABLE TO KEEP THE OTHER ACFT IN SIGHT BUT THERE WAS NO RESPONSE TO MY REPEATED RADIO CALLS. AT THAT POINT; I REQUESTED A RADIO CHK FROM PITTSFIELD UNICOM TO CONFIRM THAT MY RADIO WAS STILL XMITTING (IT WAS). THE OTHER ACFT CONTINUED AT PATTERN ALT ON WHAT MIGHT HAVE BEEN A VERY LONG DOWNWIND FOR RWY 32; AND THEN MADE A R TURN. AT THAT POINT I INITIATED A 360 DEG TURN TO THE L UP OVER PITTSFIELD'S LAKES IN ORDER TO ENSURE SEPARATION FROM THE INTRUDING ACFT. I RE-ENTERED THE PATTERN; LANDED UNEVENTFULLY; AND SAW NO MORE OF THE INTRUDING ACFT.