PA-32 PLT HAD AN NMAC WITH ANOTHER LIGHT ACFT IN APA CLASS D.

Narrative

I DEPARTED BJC IN VMC; AND HEADED S TO APA. AFTER RECEIVING THE ATIS ABOUT 15 MIN OUT; I TUNED IN THE TWR FREQ; AND FOUND IT TO BE EXTREMELY BUSY. FINALLY; AT 9 NM W OF THE ARPT; I WAS ABLE TO CONTACT THE TWR AND TOLD THEM WHERE I WAS; THAT I HAD THE ATIS; AND THAT I WAS LNDG. I WAS TOLD TO CROSS MID-FIELD AT 7300 FT MSL AND ENTER A L DOWNWIND FOR RWY 17L. I WAS AWARE OF AN ACFT APCHING THE FIELD FROM THE NW; AND ANOTHER TOLD TO ENTER THE PATTERN DOWNWIND FROM THE S. AFTER PASSING MIDFIELD I STARTED TO LET DOWN AND TURN L TO ENTER THE L PATTERN FOR RWY 17L. AS I ENTERED L DOWNWIND; THE CTLR SCOLDED ME ABOUT LETTING DOWN TOO SOON; ALTHOUGH I WAS ONLY DOWN 7225 FT MSL BY THE TIME I HAD REACHED THE DOWNWIND LEG. THE CTLR ISSUED TO ME INSTRUCTIONS FOR LNDG; AND DUE TO THE CONFUSION THAT ENSUED; I AM NOT ABSOLUTELY SURE WHAT THE INSTRUCTIONS WERE. I MAY HAVE BEEN TOLD THAT I WAS #3; ALTHOUGH I DO NOT REMEMBER IT. I WAS TOLD TO FOLLOW AN ACFT; WHICH I ASSUMED WAS AN ACFT TURNING BASE FOR RWY 17L. CONSEQUENTLY; I FOLLOWED THAT ACFT. WHILE TURNING TO FINAL I NOTICED ANOTHER ACFT APCHING ME FROM THE W. BECAUSE APA HAS PARALLEL RWYS; I ASSUMED IT WAS BOUND FOR RWY 17R. THE ACFT CONTINUED TO CLOSE WITH MY COURSE; SO I MAINTAINED A CLOSE WATCH ON IT WHILE SETTING UP FOR FINAL. THE ACFT FINALLY TURNED TO THE S AT ABOUT 300 FT AWAY IN HORIZ DISTANCE AND LESS THAN 100 FT VERT DISTANCE ABOVE ME. AT THAT POINT THE CTLR ASKED IF I HAD TURNED BASE YET; AND I REPLIED THAT I WAS ON FINAL. THE CTLR TOLD ME TO GO AROUND; WHICH I DID. THE ACFT WHICH HAD BEEN CLOSING ON ME NOTED TO THE CTLR THAT HE HAD NEARLY COLLIDED WITH ME; ALTHOUGH; AS I SAID; I HAD VISUAL CONTACT WITH THE ACFT AT ALL TIMES AND THE DISTANCES WERE SUBSTANTIAL; ALTHOUGH NOT ACCEPTABLE. AFTER RE-ENTERING THE PATTERN AND LNDG WITHOUT INCIDENT; I FINALLY HAD TIME TO REFLECT ON WHAT HAPPENED. BECAUSE OF THE BUSINESS OF THE FREQ; I MADE ASSUMPTIONS WHICH I SHOULD NOT HAVE MADE. IF I WERE INDEED TOLD I WAS NUMBER 3 TO LAND; I SHOULD HAVE ABSOLUTELY ASCERTAINED THE LOCATION OF THE 2 ACFT AHEAD OF ME. INSTEAD; I SIMPLY FOLLOWED THE ACFT AHEAD OF ME. SECONDLY; AND IN PART BECAUSE OF THE FIRST ASSUMPTION; I MADE ANOTHER ASSUMPTION; THIS ONE ABOUT THE ACFT APCHING FROM THE W. I SHOULD HAVE BROKEN INTO THE FREQ AND CONFIRMED THE SIT WITH THE CTLR BEFORE WE GOT TOO CLOSE. I NOW BELIEVE THAT THAT ACFT WAS THE #2 ACFT CLRED TO LAND; AND I ABSOLUTELY SHOULD NOT HAVE BEEN WHERE I WAS AT THAT TIME. I HAVE LEARNED THAT THE BUSIER THE ARPT AND THE BUSIER THE FREQ; THE MORE IMPORTANT IT BECOMES TO CONFIRM ANY DOUBTS ONE MAY HAVE AND NOT TO SIMPLY MAKE ASSUMPTIONS. FINALLY; WHILE NONE OF THE FOLLOWING AMELIORATES MY ACTIONS; THERE ARE SOME OTHER POINTS THAT MAY HAVE EXACERBATED THE SIT. I DO NOT BELIEVE I VIOLATED THE ALT RESTRS PLACED ON ME BY THE CTLR; OR IF I DID; IT WAS BY LESS THAN 50 FT. I ALSO BELIEVE THAT SINCE THE CTLR ASKED ME IF I HAD TURNED BASE YET WHEN I WAS ALREADY WELL INTO FINAL; IT IS POSSIBLE THAT THE CTLR HAD MISTAKEN ANOTHER ACFT THAT WAS ENTERING THE PATTERN FROM THE S AS MY ACFT THAT THOUGHT THAT SHE HAD SUBSTANTIAL SEPARATION. THE CTLR WAS EXTREMELY BUSY; HAVING PROBS JUGGLING ALL THE REQUESTS; AND TWICE SEEMED TO MISTAKE OTHER ACFT IN THE PATTERN.