Narrative:

I approved a ZOA (sector 45) request for small transport X to enter my airspace descending to FL140 on V165 northwest of fmg. Air carrier Y was inbound on the same airway descending to FL160. Air carrier Z was also inbound via anaho intersection, and was assigned heading 240 degrees by ZOA. I expedited both air carrier Z and X through FL150 to make room for air carrier Y to enter my airspace. I vectored Z to the airport to be #1. I vectored X to a heading of 200 degrees to take him west to final where he could be sequenced later. I turned Y east to heading 100 degrees both for descent, and to follow Z. I turned Y west to heading 230 degrees to bring him back to the final. I slowed Y to 210 KTS, and gave him clearance to descend through X's altitude, and cleared him for a visual approach to runway 16L 1-2 NM northeast of spk NDB. Y did not turn toward the airport, and appeared to fly the ground track of the sparks visual runway 16R approach (a charted visual approach to rno). When I cleared Y for a visual approach, I attempted to turn X west to heading 230 degrees, but I was blocked by Y. I later gave X an immediate right turn to try to save as much separation as possible. X was surprised by my immediate turn, and did not turn. I then issued traffic to Y who saw the CY21. Several procedural factors and mistakes by me contributed to this incident. X was inbound on the same route of flight as Y, and forced ZOA to keep Y on their frequency and above my airspace. This forced me to take Y off final because he was too high to make a straight in approach. When I cleared Y for a visual approach he was still high, but in my opinion should have been able to proceed straight in to the airport. Y would not have been in conflict with X had they turned straight in. Y appeared to fly the sparks visual approach, but may have gone west of final to allow room for descent. When ZOA handed off Y I felt it would be possible to fit all the inbound aircraft into a sequence, but I would have very little room for error. I should have kept Y at a high altitude and vectored that aircraft into another traffic flow, effectively taking Y out of the sequence. Once I decided to sequence Y to the airport I should have anticipated Y going through final, and vectored X west sooner. I also had a problem with frequency congestion. I would wait as long as I could for a readback before issuing another instruction. On 2 occasions instructions which would have provided separation were blocked by aircraft giving a delayed readback of a previous instruction. If I had quickly re-issued instructions, or waited for an aircraft to read back their instructions, separation would have existed.

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Original NASA ASRS Text

Title: SMT X HAD LTSS FROM ACR Y. SYS ERROR.

Narrative: I APPROVED A ZOA (SECTOR 45) REQUEST FOR SMT X TO ENTER MY AIRSPACE DSNDING TO FL140 ON V165 NW OF FMG. ACR Y WAS INBOUND ON THE SAME AIRWAY DSNDING TO FL160. ACR Z WAS ALSO INBOUND VIA ANAHO INTXN, AND WAS ASSIGNED HDG 240 DEGS BY ZOA. I EXPEDITED BOTH ACR Z AND X THROUGH FL150 TO MAKE ROOM FOR ACR Y TO ENTER MY AIRSPACE. I VECTORED Z TO THE ARPT TO BE #1. I VECTORED X TO A HDG OF 200 DEGS TO TAKE HIM W TO FINAL WHERE HE COULD BE SEQUENCED LATER. I TURNED Y E TO HDG 100 DEGS BOTH FOR DSCNT, AND TO FOLLOW Z. I TURNED Y W TO HDG 230 DEGS TO BRING HIM BACK TO THE FINAL. I SLOWED Y TO 210 KTS, AND GAVE HIM CLRNC TO DSND THROUGH X'S ALT, AND CLRED HIM FOR A VISUAL APCH TO RWY 16L 1-2 NM NE OF SPK NDB. Y DID NOT TURN TOWARD THE ARPT, AND APPEARED TO FLY THE GND TRACK OF THE SPARKS VISUAL RWY 16R APCH (A CHARTED VISUAL APCH TO RNO). WHEN I CLRED Y FOR A VISUAL APCH, I ATTEMPTED TO TURN X W TO HDG 230 DEGS, BUT I WAS BLOCKED BY Y. I LATER GAVE X AN IMMEDIATE R TURN TO TRY TO SAVE AS MUCH SEPARATION AS POSSIBLE. X WAS SURPRISED BY MY IMMEDIATE TURN, AND DID NOT TURN. I THEN ISSUED TFC TO Y WHO SAW THE CY21. SEVERAL PROCEDURAL FACTORS AND MISTAKES BY ME CONTRIBUTED TO THIS INCIDENT. X WAS INBOUND ON THE SAME RTE OF FLT AS Y, AND FORCED ZOA TO KEEP Y ON THEIR FREQ AND ABOVE MY AIRSPACE. THIS FORCED ME TO TAKE Y OFF FINAL BECAUSE HE WAS TOO HIGH TO MAKE A STRAIGHT IN APCH. WHEN I CLRED Y FOR A VISUAL APCH HE WAS STILL HIGH, BUT IN MY OPINION SHOULD HAVE BEEN ABLE TO PROCEED STRAIGHT IN TO THE ARPT. Y WOULD NOT HAVE BEEN IN CONFLICT WITH X HAD THEY TURNED STRAIGHT IN. Y APPEARED TO FLY THE SPARKS VISUAL APCH, BUT MAY HAVE GONE W OF FINAL TO ALLOW ROOM FOR DSCNT. WHEN ZOA HANDED OFF Y I FELT IT WOULD BE POSSIBLE TO FIT ALL THE INBOUND ACFT INTO A SEQUENCE, BUT I WOULD HAVE VERY LITTLE ROOM FOR ERROR. I SHOULD HAVE KEPT Y AT A HIGH ALT AND VECTORED THAT ACFT INTO ANOTHER TFC FLOW, EFFECTIVELY TAKING Y OUT OF THE SEQUENCE. ONCE I DECIDED TO SEQUENCE Y TO THE ARPT I SHOULD HAVE ANTICIPATED Y GOING THROUGH FINAL, AND VECTORED X W SOONER. I ALSO HAD A PROB WITH FREQ CONGESTION. I WOULD WAIT AS LONG AS I COULD FOR A READBACK BEFORE ISSUING ANOTHER INSTRUCTION. ON 2 OCCASIONS INSTRUCTIONS WHICH WOULD HAVE PROVIDED SEPARATION WERE BLOCKED BY ACFT GIVING A DELAYED READBACK OF A PREVIOUS INSTRUCTION. IF I HAD QUICKLY RE-ISSUED INSTRUCTIONS, OR WAITED FOR AN ACFT TO READ BACK THEIR INSTRUCTIONS, SEPARATION WOULD HAVE EXISTED.

Data retrieved from NASA's ASRS site as of July 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.