Narrative:

Small aircraft X was on an ILS approach to runway 13R. Small aircraft Y on downwind was sequenced to follow small aircraft X on a 2 mi final. I restated the sequence for small aircraft Y with small aircraft X on short final and cleared him to land. Both times small aircraft Y answered by his call sign only. I turned around to look at other traffic and small aircraft X said 'I've got traffic off our right wing, we're diving under him and he's dropping on us.' I told small aircraft Y to turn right and overfly the west grass because I had a helicopter on the west taxiway. I then sent small aircraft Y around. Both pilots were requested to call the tower. Small aircraft Y said he never saw his traffic and he sounded like a foreigner (over the air he did not sound foreign or confused). Small aircraft X said he thought small aircraft Y was within 50' off his right wing and to avoid the aircraft he dove for the runway. In my opinion it was never that close, however, small aircraft Y must of cranked it in direct after his clearance to land. I regret not having eyes in back of my head to watch every move these pilots make. This will make me more aware and I will get a confirmation that the pilot has his traffic in sight instead of just a call sign read back. If I have any doubt about the situation or the pilot has doubts, I will send the appropriate aircraft around immediately, instead of jockeying the aircraft around to make it work.

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Original NASA ASRS Text

Title: SMA ON BASE LEG DID NOT FOLLOW ATC INSTRUCTIONS AND CONFLICTED WITH ANOTHER ACFT ON FINAL.

Narrative: SMA X WAS ON AN ILS APCH TO RWY 13R. SMA Y ON DOWNWIND WAS SEQUENCED TO FOLLOW SMA X ON A 2 MI FINAL. I RESTATED THE SEQUENCE FOR SMA Y WITH SMA X ON SHORT FINAL AND CLRED HIM TO LAND. BOTH TIMES SMA Y ANSWERED BY HIS CALL SIGN ONLY. I TURNED AROUND TO LOOK AT OTHER TFC AND SMA X SAID 'I'VE GOT TFC OFF OUR RIGHT WING, WE'RE DIVING UNDER HIM AND HE'S DROPPING ON US.' I TOLD SMA Y TO TURN RIGHT AND OVERFLY THE W GRASS BECAUSE I HAD A HELI ON THE W TXWY. I THEN SENT SMA Y AROUND. BOTH PLTS WERE REQUESTED TO CALL THE TWR. SMA Y SAID HE NEVER SAW HIS TFC AND HE SOUNDED LIKE A FOREIGNER (OVER THE AIR HE DID NOT SOUND FOREIGN OR CONFUSED). SMA X SAID HE THOUGHT SMA Y WAS WITHIN 50' OFF HIS RIGHT WING AND TO AVOID THE ACFT HE DOVE FOR THE RWY. IN MY OPINION IT WAS NEVER THAT CLOSE, HOWEVER, SMA Y MUST OF CRANKED IT IN DIRECT AFTER HIS CLRNC TO LAND. I REGRET NOT HAVING EYES IN BACK OF MY HEAD TO WATCH EVERY MOVE THESE PLTS MAKE. THIS WILL MAKE ME MORE AWARE AND I WILL GET A CONFIRMATION THAT THE PLT HAS HIS TFC IN SIGHT INSTEAD OF JUST A CALL SIGN READ BACK. IF I HAVE ANY DOUBT ABOUT THE SITUATION OR THE PLT HAS DOUBTS, I WILL SEND THE APPROPRIATE ACFT AROUND IMMEDIATELY, INSTEAD OF JOCKEYING THE ACFT AROUND TO MAKE IT WORK.

Data retrieved from NASA's ASRS site as of August 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.