Narrative:

I was working a departure rush on a low altitude sector. There were 3 overflts with the majority of the traffic being turbojets climbing from the airport. The traffic complexity was rapidly increasing so I asked for assistance. There was a swbound mlt at FL180. The turbojets are transferred to the center climbing wbound to 17000 ft. I climbed several aircraft to FL230 and some were stopped at FL200 for an overflt at FL210. No temporary altitudes were entered into the data block. I went back to an aircraft thought to be in conflict with the medium large transport and stopped him at 17000 ft. Another jet checked on and I left him at 17000 ft. I thought I had stopped yet another aircraft, air carrier Y, at 17000 ft. I was extremely busy by this time. I issued traffic to air carrier Y 'traffic 2 O'clock, 2 mi, swbound at FL180.' air carrier Y acknowledges 'in sight.' I then issued traffic to the mlt, 'traffic 9-10 O'clock, 2 mi, wbound, climbing to 17000 ft.' the medium large transport acknowledges traffic in sight. The next thing I noticed was air carrier Y mode C indicating 17600 ft. I asked him to verify level at 17000 ft and he replied, 'no we were cleared to FL230 and we had the traffic in sight.' the aircraft's closest proximity was 1 mi and 100 ft. Several factors can be learned from this incident: 1) the use of temporary altitudes in the data blocks. 2) when issuing traffic, restate the altitude to be maintained. 3) staff sectors sooner so you can have the extra scanning. I am not sure how many pilots are aware of separation standards for various facilities. The pilot of air carrier Y received an RA but he did not respond to it because he had visual. We cannot use visual separation in the center environment. Both pilots heard the TA's. Had the pilot of air carrier Y questioned the assigned altitude after hearing the TA to the mlt this situation may not have occurred. Another deficiency is the staffing. We continually work short staffed. This situation occurred during a known rush time and was not fully staffed prior to the controller getting very busy.

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Original NASA ASRS Text

Title: ACR Y CLB THROUGH OCCUPIED ALT HAD LTSS FROM MLT. SYS ERROR.

Narrative: I WAS WORKING A DEP RUSH ON A LOW ALT SECTOR. THERE WERE 3 OVERFLTS WITH THE MAJORITY OF THE TFC BEING TURBOJETS CLBING FROM THE ARPT. THE TFC COMPLEXITY WAS RAPIDLY INCREASING SO I ASKED FOR ASSISTANCE. THERE WAS A SWBOUND MLT AT FL180. THE TURBOJETS ARE TRANSFERRED TO THE CTR CLBING WBOUND TO 17000 FT. I CLBED SEVERAL ACFT TO FL230 AND SOME WERE STOPPED AT FL200 FOR AN OVERFLT AT FL210. NO TEMPORARY ALTS WERE ENTERED INTO THE DATA BLOCK. I WENT BACK TO AN ACFT THOUGHT TO BE IN CONFLICT WITH THE MLG AND STOPPED HIM AT 17000 FT. ANOTHER JET CHKED ON AND I LEFT HIM AT 17000 FT. I THOUGHT I HAD STOPPED YET ANOTHER ACFT, ACR Y, AT 17000 FT. I WAS EXTREMELY BUSY BY THIS TIME. I ISSUED TFC TO ACR Y 'TFC 2 O'CLOCK, 2 MI, SWBOUND AT FL180.' ACR Y ACKNOWLEDGES 'IN SIGHT.' I THEN ISSUED TFC TO THE MLT, 'TFC 9-10 O'CLOCK, 2 MI, WBOUND, CLBING TO 17000 FT.' THE MLG ACKNOWLEDGES TFC IN SIGHT. THE NEXT THING I NOTICED WAS ACR Y MODE C INDICATING 17600 FT. I ASKED HIM TO VERIFY LEVEL AT 17000 FT AND HE REPLIED, 'NO WE WERE CLRED TO FL230 AND WE HAD THE TFC IN SIGHT.' THE ACFT'S CLOSEST PROX WAS 1 MI AND 100 FT. SEVERAL FACTORS CAN BE LEARNED FROM THIS INCIDENT: 1) THE USE OF TEMPORARY ALTS IN THE DATA BLOCKS. 2) WHEN ISSUING TFC, RESTATE THE ALT TO BE MAINTAINED. 3) STAFF SECTORS SOONER SO YOU CAN HAVE THE EXTRA SCANNING. I AM NOT SURE HOW MANY PLTS ARE AWARE OF SEPARATION STANDARDS FOR VARIOUS FACILITIES. THE PLT OF ACR Y RECEIVED AN RA BUT HE DID NOT RESPOND TO IT BECAUSE HE HAD VISUAL. WE CANNOT USE VISUAL SEPARATION IN THE CTR ENVIRONMENT. BOTH PLTS HEARD THE TA'S. HAD THE PLT OF ACR Y QUESTIONED THE ASSIGNED ALT AFTER HEARING THE TA TO THE MLT THIS SIT MAY NOT HAVE OCCURRED. ANOTHER DEFICIENCY IS THE STAFFING. WE CONTINUALLY WORK SHORT STAFFED. THIS SIT OCCURRED DURING A KNOWN RUSH TIME AND WAS NOT FULLY STAFFED PRIOR TO THE CTLR GETTING VERY BUSY.

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.