C182 PLT FAILS TO SEE OR HEAR ACFT ON SHORT FINAL AT 1S0 AND CROSSED HOLD LINE(S).

Narrative

IT WAS A BUSY SUNDAY AFTERNOON AT PIERCE COUNTY ARPT (1S0); PUYALLUP; WA. I WAS PIC OF A C182. I HAD COMPLETED MY BEFORE TKOF CHK; WAITED FOR 2 ACFT TO TAKE OFF; AND WAS HOLDING SHORT FOR TKOF ON RWY 34. I WAITED FOR AN ACFT TO LAND THAT HAD CALLED FINAL AND THAT I HAD VISUAL CONTACT WITH. AFTER ACFT CLRED RWY; I CHKED FINAL FOR TFC; CALLED MY INTENTION TO TAKE OFF BY BROADCASTING ON UNICOM 122.7; AND BEGAN TO TAXI FOR TKOF. AFTER I CROSSED THE HOLD SHORT LINE; A PLT CALLED STATING THAT HE WAS ON FINAL. THIS WAS THE FIRST CALL I HEARD FROM THE AIRPLANE AND THE FIRST CALL HEARD BY THE 2 OTHER CREW MEMBERS IN MY ACFT. I HAD INSUFFICIENT SPACE TO TURN AROUND; SO I HELD MY POS. I THEN ACQUIRED VISUAL WITH A TWIN BARON THAT WAS ON A 1-2 MI FINAL; WHICH SUBSEQUENTLY LANDED. HE PASSED ABOUT 20 FT IN FRONT OF MY NOSE; AT ABOUT AN ALT OF 40 FT; AND AT ABOUT 100 KTS. HE LANDED ABOUT 400 FT DOWN THE RWY. AFTER HE CLRED THE RWY; I TOOK OFF. NO INCIDENT OCCURRED. NOT HEARING THE TWIN BARON BROADCAST HIS INTENTIONS TO PIERCE COUNTY ARPT TFC CAUSED THE PROB. POSSIBLY HE MADE NO CALLS OTHER THAN WHEN HE WAS ON FINAL. POSSIBLY HE WAS BROADCASTING WHEN OTHER ACFT WERE BROADCASTING AND WAS CUT OUT. OR POSSIBLY THERE IS SOME OTHER COMS FAILURE. A SIT LIKE THIS ONE CAN BE PREVENTED IF ALL ACFT AT AN UNCTLED ARPT ENTER AND BROADCAST THAT THEY ARE ON DOWNWIND; BROADCAST THAT THEY ARE ON BASE; AND BROADCAST ON FINAL.