Narrative:

I was monitoring a radar trnee at pxv hi sector, radar position. During this time we experienced problems with the handoff lines. The trnee and I changed jacks and the problem still remained. We reported the problem to the area supervisor in charge. During all this time traffic was increasing in vol and complexity. Air carrier X, at FL390, inquired about the ride at FL350 and was informed no adverse reports at that altitude. Air carrier X requested FL350 at the same time the NAS specialist approached the sector to inquire about the handoff line problem. While my attention was diverted to the conversation with the NAS specialist concerning the handoff line problem, the trnee cleared air carrier X to descend to FL350. I did not hear the trnee give the descent clearance to X because of my conversation with the NAS specialist about the equipment problem. Air carrier Y at FL370 was traffic for X, crossing left to right. When my conversation with the NAS specialist was complete I returned all of my attention to the radar and realized that air carrier X was descending. Mode C readout showed X at FL384 descending to FL350. I immediately cleared air carrier X to climb to FL390 for traffic. X reported leaving FL380 for FL390. Sep was lost seconds later. Supplemental information from acn 91939: I, as a radar trnee, cleared air carrier X to FL350 west/O noticing that air carrier Y, who had been given frequency change to another sector, was traffic. Aircraft came within 1000' and 3.8 mi.

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Original NASA ASRS Text

Title: LESS THAN STANDARD SEPARATION BETWEEN 2 ACR. OPERATIONAL ERROR.

Narrative: I WAS MONITORING A RADAR TRNEE AT PXV HI SECTOR, RADAR POS. DURING THIS TIME WE EXPERIENCED PROBS WITH THE HDOF LINES. THE TRNEE AND I CHANGED JACKS AND THE PROB STILL REMAINED. WE RPTED THE PROB TO THE AREA SUPVR IN CHARGE. DURING ALL THIS TIME TFC WAS INCREASING IN VOL AND COMPLEXITY. ACR X, AT FL390, INQUIRED ABOUT THE RIDE AT FL350 AND WAS INFORMED NO ADVERSE RPTS AT THAT ALT. ACR X REQUESTED FL350 AT THE SAME TIME THE NAS SPECIALIST APCHED THE SECTOR TO INQUIRE ABOUT THE HDOF LINE PROB. WHILE MY ATTN WAS DIVERTED TO THE CONVERSATION WITH THE NAS SPECIALIST CONCERNING THE HDOF LINE PROB, THE TRNEE CLRED ACR X TO DSND TO FL350. I DID NOT HEAR THE TRNEE GIVE THE DSCNT CLRNC TO X BECAUSE OF MY CONVERSATION WITH THE NAS SPECIALIST ABOUT THE EQUIP PROB. ACR Y AT FL370 WAS TFC FOR X, XING LEFT TO RIGHT. WHEN MY CONVERSATION WITH THE NAS SPECIALIST WAS COMPLETE I RETURNED ALL OF MY ATTN TO THE RADAR AND REALIZED THAT ACR X WAS DSNDING. MODE C READOUT SHOWED X AT FL384 DSNDING TO FL350. I IMMEDIATELY CLRED ACR X TO CLB TO FL390 FOR TFC. X RPTED LEAVING FL380 FOR FL390. SEP WAS LOST SECS LATER. SUPPLEMENTAL INFO FROM ACN 91939: I, AS A RADAR TRNEE, CLRED ACR X TO FL350 W/O NOTICING THAT ACR Y, WHO HAD BEEN GIVEN FREQ CHANGE TO ANOTHER SECTOR, WAS TFC. ACFT CAME WITHIN 1000' AND 3.8 MI.

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.