BONANZA LANDS OVER A C172 AT PNC.

Narrative

UPON LEAVING THE TERMINAL TIE-DOWN AREA; I MADE THE CALL ON UNICOM STATING MY TAXI INTENTIONS. WHILE DOING RUN-UP ON THE TXWY NEAR THE APCH END OF RWY 35; I MONITORED THE UNICOM FREQ AND CHKED ASOS ONE MORE TIME. I ALSO NOTED AN ACFT IN THE PATTERN THAT APPARENTLY WAS NOT MAKING CALLS OR DID NOT HAVE A RADIO. IT SEEMED LOGICAL; BEING A SMALL CROP DUSTER TYPE; THAT THE PLANE DID NOT HAVE A RADIO AND WAS NOT RESPONDING IN ANY WAY. I FAILED TO MAKE A COM CHK TO SEE IF I WAS BEING HEARD. I THEN IMPUTED THE MCALLISTER FSS AND THE CTR FREQS ON COM #2. I LOOKED AROUND THE PATTERN THE BEST I COULD WHILE FACING E IN A HIGH WING AIRPLANE. I WAITED FOR THE PLANE I HAD SEEN EARLIER TO COME INTO VIEW ON BASE; ASSUMING HE HAD NOT DEPARTED THE PATTERN. A FEW MOMENTS LATER; I SPOTTED THE SMALL PLANE WHERE I HAD ANTICIPATED. I THEN CALLED ON THE UNICOM MY INTENTIONS TO TKOF AFTER THE ACFT ON BASE. WHEN THE PLANE TOUCHED DOWN; I CALLED A TAXI TO TKOF POS AND HOLDING FOR DEPARTING TFC (HE WAS DOING TOUCH-AND-GOES AND WAS VERY SLOW; SO I WANTED TO GIVE HIM AMPLE TIME). APPROX 10 SECONDS AFTER I TURNED TO FACE DOWN THE CTR OF THE RWY; WHAT I THINK WAS A BEECH BONANZA FLEW OVER MY ACFT FOR LNDG ABOUT AT THE 1000 FT MARKERS OF THE RWY. I FUSSED WITH THE RADIOS; MY MIKE CABLES AND CHKED THE FREQ AGAIN. ALL WAS GOOD AND CORRECT. I IMMEDIATELY CALLED FOR A COM CHK. HEARING A VERY QUIET RESPONSE; I TURNED UP THE RADIO TO HEAR AN ACFT WHICH HAD BEEN TAXIING TO TAKE OFF AS WELL SAY THAT THE DEPARTING ACFT HAD NO RADIO. I SAID I HEARD NOTHING OF AN APCHING PLANE; AND COULD NOT SEE ANYONE ELSE IN THE PATTERN. WHAT MUST HAVE BEEN THE LNDG ACFT RADIOED IN RESPONSE; 'I CALLED ALL POS.' IN A SOMEWHAT QUIET VOICE. THIS INCIDENT CLRLY WOULD HAVE BEEN AVOIDED IF I HAD THE RADIO TURNED UP TO A HIGHER LEVEL. I WOULD HAVE BEEN AWARE OF THE ISSUE IF I HAD DONE A COM CHK. I ALSO MAY HAVE NOTED AN 'R' IN THE RADIO FREQ WINDOW DURING ANY RECEPTION OF ANOTHER ACFT'S CALLS. I ALSO HAD MADE THE ASSUMPTION THAT THE VOLUME SETTING I HAD USED FOR ASOS WAS ADEQUATE FOR UNICOM AIR TFC. IT ALSO BOTHERS ME THAT THE ACFT LANDED AT ALL. THE ACFT WAS NOT ON SHORT FINAL; AND I SIMPLY COULD NOT SEE HIM. HE COULD SEE ME (OR AT LEAST SHOULD HAVE). THE LNDG PLANE CAME IN AT 80 KTS OR SO; MEANING HE WAS AT LEAST 3/4 MI AT MY CALL THAT I WAS GOING TO TAXI TO POS.