Narrative:

I worked 2 hours and 16 mins (I had told the supervisor at 2 hours I needed a break) at imperial sector with extremely heavy traffic, took 24 min break. Worked 22 min imperial 'D' side, then went to 2 radar for 40 mins of very complex traffic before the occurrence. I had 3 wbound jets at FL310, 1 northbound jet at FL290. Plus about 10 other aircraft on my pvd. Traffic was complex due to turbulence. Aircraft wanted lower altitudes, causing a lot of crossing and transitioning. Northbound air carrier X FL290 was issued traffic on air carrier Y 2 O'clock 10 mi wbound at FL310, then I changed the communications to 120.02 and dropped the full data block as the aircraft left my airspace. Then an aircraft deviated from altitude assignment and route. Next wbound air carrier Y requested lower for chop. (I had previously obtained control for lower on the 3 wbounds.) I had forgot about air carrier X and couldn't see the limited data block because air carrier Y full data block was covering it. I descend air carrier Y to FL280. A min later the conflict alert was activated. I climbed air carrier Y back to FL310, air carrier Y said he was at FL300, should he climb? I observed the targets diverging by about 90 degree and 3 mi, and there was no danger. So I told air carrier Y to continue to FL280 and issued traffic. Air carrier Y advised he had been watching the traffic, and was also on TCASII. Had I not been so exhausted, this may have been avoided. Supplemental information from acn 189476: northbound air carrier X at FL290 exiting air sector's airspace. Wbound aircraft at FL310 asked for descent due to chop. Air carrier Y was descended through the airspace of the northbound aircraft. The evening was a very busy one with long shifts and few breaks with a difficult workload.

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Original NASA ASRS Text

Title: ACR Y DSCNT THROUGH OCCUPIED ALT HAD LTSS FROM ACR X. SYS ERROR.

Narrative: I WORKED 2 HRS AND 16 MINS (I HAD TOLD THE SUPVR AT 2 HRS I NEEDED A BREAK) AT IMPERIAL SECTOR WITH EXTREMELY HVY TFC, TOOK 24 MIN BREAK. WORKED 22 MIN IMPERIAL 'D' SIDE, THEN WENT TO 2 RADAR FOR 40 MINS OF VERY COMPLEX TFC BEFORE THE OCCURRENCE. I HAD 3 WBOUND JETS AT FL310, 1 NBOUND JET AT FL290. PLUS ABOUT 10 OTHER ACFT ON MY PVD. TFC WAS COMPLEX DUE TO TURB. ACFT WANTED LOWER ALTS, CAUSING A LOT OF XING AND TRANSITIONING. NBOUND ACR X FL290 WAS ISSUED TFC ON ACR Y 2 O'CLOCK 10 MI WBOUND AT FL310, THEN I CHANGED THE COMS TO 120.02 AND DROPPED THE FULL DATA BLOCK AS THE ACFT LEFT MY AIRSPACE. THEN AN ACFT DEVIATED FROM ALT ASSIGNMENT AND RTE. NEXT WBOUND ACR Y REQUESTED LOWER FOR CHOP. (I HAD PREVIOUSLY OBTAINED CTL FOR LOWER ON THE 3 WBOUNDS.) I HAD FORGOT ABOUT ACR X AND COULDN'T SEE THE LIMITED DATA BLOCK BECAUSE ACR Y FULL DATA BLOCK WAS COVERING IT. I DSND ACR Y TO FL280. A MIN LATER THE CONFLICT ALERT WAS ACTIVATED. I CLBED ACR Y BACK TO FL310, ACR Y SAID HE WAS AT FL300, SHOULD HE CLB? I OBSERVED THE TARGETS DIVERGING BY ABOUT 90 DEG AND 3 MI, AND THERE WAS NO DANGER. SO I TOLD ACR Y TO CONTINUE TO FL280 AND ISSUED TFC. ACR Y ADVISED HE HAD BEEN WATCHING THE TFC, AND WAS ALSO ON TCASII. HAD I NOT BEEN SO EXHAUSTED, THIS MAY HAVE BEEN AVOIDED. SUPPLEMENTAL INFO FROM ACN 189476: NBOUND ACR X AT FL290 EXITING AIR SECTOR'S AIRSPACE. WBOUND ACFT AT FL310 ASKED FOR DSCNT DUE TO CHOP. ACR Y WAS DSNDED THROUGH THE AIRSPACE OF THE NBOUND ACFT. THE EVENING WAS A VERY BUSY ONE WITH LONG SHIFTS AND FEW BREAKS WITH A DIFFICULT WORKLOAD.

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.