Narrative:

Small aircraft X over the sac VOR northeast bound at 8000' descending to 7000', that the controller thought was level at 8000, and air carrier Y departing smf sebnd climbing to 11000'. Air carrier Y was restr to 7000' to avoid small aircraft X at 8000'. When the controller saw small aircraft X at 7000', he knew he had restr air carrier Y 1000' below small aircraft X so he expected air carrier Y to stop the climb at 6000'. When air carrier Y was at 6200' the controller advised air carrier Y to maintain 6000'. Air carrier Y and small aircraft X got within 1 mi and 300', before the air carrier Y descended back to 6000'. Air carrier Y had to be issued an immediate descent to avoid the collision. The situation occurred because the controller was preoccupied with another aircraft which was VFR and caught in clouds. Also he assumed too many things, the altitude of small aircraft X and his altitude restriction to air carrier Y. This could have been prevented by the controller reissuing the altitude restriction to the small aircraft X, he could have asked the small aircraft X his assigned altitude, he should have known that northeast bound traffic is an odd altitude. Callback conversation with reporter revealed the following: reporter experience: 7 yrs radar, 2 yrs non radar, 5 yrs military. He has been an fpl at sac approach control for only 8 months. Reporter stated conflict alert caused him to scan for a confliction. He was working a GA aircraft that was VFR and gotten into the clouds. FAA facility management filed an operational error. Supplemental information from acn 143174: air carrier Y departure smf with a frogo 5 fra transition and clearance to 11000'. At approximately 4-5000' we were advised by departure to maintain 7000' which we read back and set in our altitude arm. At approximately 6000' the captain verified with the first officer that we were now only cleared to 7000'. At approximately 6400' departure called and advised us that we were only cleared to 6000'. At the time we were experiencing a nuisance warning light and tuning the radar as we were IFR. We stopped our climb at 6600' and began an immediate descent to 6000'. The controller called back again and said to descend immediately to 6000' as there was an small aircraft at 7000' and 1 mi. We had no visual contact with the small aircraft. No abrupt maneuvers were required and no injuries incurred. The captain called smf approach after arriving in burbank. We were told that the tapes clearly indicated the controller issued us a clearance to 7000'. We were also told that the controller was working a lost aircraft at the time which contributed to his mistake. The controller also at one point referred to an small transport at 7000' which later proved to be the small aircraft.

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Original NASA ASRS Text

Title: SMA X HAD LESS THAN STANDARD SEPARATION FROM ACR Y. SYSTEM ERROR.

Narrative: SMA X OVER THE SAC VOR NE BOUND AT 8000' DESCENDING TO 7000', THAT THE CTLR THOUGHT WAS LEVEL AT 8000, AND ACR Y DEPARTING SMF SEBND CLIMBING TO 11000'. ACR Y WAS RESTR TO 7000' TO AVOID SMA X AT 8000'. WHEN THE CTLR SAW SMA X AT 7000', HE KNEW HE HAD RESTR ACR Y 1000' BELOW SMA X SO HE EXPECTED ACR Y TO STOP THE CLIMB AT 6000'. WHEN ACR Y WAS AT 6200' THE CTLR ADVISED ACR Y TO MAINTAIN 6000'. ACR Y AND SMA X GOT WITHIN 1 MI AND 300', BEFORE THE ACR Y DESCENDED BACK TO 6000'. ACR Y HAD TO BE ISSUED AN IMMEDIATE DSNT TO AVOID THE COLLISION. THE SITUATION OCCURRED BECAUSE THE CTLR WAS PREOCCUPIED WITH ANOTHER ACFT WHICH WAS VFR AND CAUGHT IN CLOUDS. ALSO HE ASSUMED TOO MANY THINGS, THE ALT OF SMA X AND HIS ALT RESTRICTION TO ACR Y. THIS COULD HAVE BEEN PREVENTED BY THE CTLR REISSUING THE ALT RESTRICTION TO THE SMA X, HE COULD HAVE ASKED THE SMA X HIS ASSIGNED ALT, HE SHOULD HAVE KNOWN THAT NE BOUND TFC IS AN ODD ALT. CALLBACK CONVERSATION WITH REPORTER REVEALED THE FOLLOWING: REPORTER EXPERIENCE: 7 YRS RADAR, 2 YRS NON RADAR, 5 YRS MIL. HE HAS BEEN AN FPL AT SAC APCH CTL FOR ONLY 8 MONTHS. REPORTER STATED CONFLICT ALERT CAUSED HIM TO SCAN FOR A CONFLICTION. HE WAS WORKING A GA ACFT THAT WAS VFR AND GOTTEN INTO THE CLOUDS. FAA FAC MGMNT FILED AN OPERATIONAL ERROR. SUPPLEMENTAL INFORMATION FROM ACN 143174: ACR Y DEP SMF WITH A FROGO 5 FRA TRANSITION AND CLRNC TO 11000'. AT APPROX 4-5000' WE WERE ADVISED BY DEP TO MAINTAIN 7000' WHICH WE READ BACK AND SET IN OUR ALT ARM. AT APPROX 6000' THE CAPT VERIFIED WITH THE F/O THAT WE WERE NOW ONLY CLRED TO 7000'. AT APPROX 6400' DEP CALLED AND ADVISED US THAT WE WERE ONLY CLRED TO 6000'. AT THE TIME WE WERE EXPERIENCING A NUISANCE WARNING LIGHT AND TUNING THE RADAR AS WE WERE IFR. WE STOPPED OUR CLIMB AT 6600' AND BEGAN AN IMMEDIATE DSNT TO 6000'. THE CTLR CALLED BACK AGAIN AND SAID TO DSND IMMEDIATELY TO 6000' AS THERE WAS AN SMA AT 7000' AND 1 MI. WE HAD NO VISUAL CONTACT WITH THE SMA. NO ABRUPT MANEUVERS WERE REQUIRED AND NO INJURIES INCURRED. THE CAPT CALLED SMF APCH AFTER ARRIVING IN BURBANK. WE WERE TOLD THAT THE TAPES CLEARLY INDICATED THE CTLR ISSUED US A CLRNC TO 7000'. WE WERE ALSO TOLD THAT THE CTLR WAS WORKING A LOST ACFT AT THE TIME WHICH CONTRIBUTED TO HIS MISTAKE. THE CTLR ALSO AT ONE POINT REFERRED TO AN SMT AT 7000' WHICH LATER PROVED TO BE THE SMA.

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.