Narrative:

Sector 70 called me on R-95 and showed me 2 aircraft air carrier X and air carrier Y coming to my sector in confliction at FL330. Sector 70 said they would turn X direct txo to fix the problem, I agreed and took the handoffs. The same interphone call, sector 70 showed me another 'pair' at FL370 (military jet and a bizjet) said they had to hold on the military jet for other traffic, then would turn him behind the bizjet. I agreed and took the handoffs. A min or so later, I viewed the vector line projected separation between X and Y at 10 mi or more. The conflict alert was then activated on the FL370 traffic. This distracted me to this situation and I checked to see if the aircraft was on frequency, he was not. Looking back at the FL330 traffic I noticed Y had started a substantial left turn. I instructed X to turn 40 degree right (right as or after conflict alert was activated). He acknowledged, I immediately turned Y 15 degrees right. (There was no response, so I expedited X down to FL310). Standard separation was lost at 4.56 mi 6 seconds before X reported level at FL310. Y was then raised and questioned, he replied he was on course over lvs. 1) on numerous occasions, aircraft had to be called several times before they answered. 2) I thought Y was assigned present heading, he was not. 3) Y made about a 20 degree left turn across the airway in front of X. Supplemental information from acn 303180: air carrier Y checked in on new ZAB frequency -- lots of chatter on the frequency. Few mins later ZAB called to ask why we had not made a heading change that he had supposedly given us previously. Neither the captain nor I had received or acknowledged that directive from ATC. Evidently another aircraft air carrier X was given vectors/altitude change for separation integrity on us because of our heading/altitude. It was obvious that the controller was very busy when we checked in on his frequency. Also a flight attendant was in the cockpit at the time requesting flight information. It is possible that the controller gave us the call but we did not hear or acknowledge because of radio/flight attendant distrs. As a crew, our only request is that if the controller does not receive an acknowledgement from us that he repeat the command, speak louder to get our attention (if still no acknowledgement), or assume that we did not receive the transmission and are therefore unable to comply with requested flight changes.

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Original NASA ASRS Text

Title: ACR X SAME ALT ASSIGNED HAD LTSS FROM ACR Y. SYS ERROR.

Narrative: SECTOR 70 CALLED ME ON R-95 AND SHOWED ME 2 ACFT ACR X AND ACR Y COMING TO MY SECTOR IN CONFLICTION AT FL330. SECTOR 70 SAID THEY WOULD TURN X DIRECT TXO TO FIX THE PROB, I AGREED AND TOOK THE HDOFS. THE SAME INTERPHONE CALL, SECTOR 70 SHOWED ME ANOTHER 'PAIR' AT FL370 (MIL JET AND A BIZJET) SAID THEY HAD TO HOLD ON THE MIL JET FOR OTHER TFC, THEN WOULD TURN HIM BEHIND THE BIZJET. I AGREED AND TOOK THE HDOFS. A MIN OR SO LATER, I VIEWED THE VECTOR LINE PROJECTED SEPARATION BTWN X AND Y AT 10 MI OR MORE. THE CONFLICT ALERT WAS THEN ACTIVATED ON THE FL370 TFC. THIS DISTRACTED ME TO THIS SIT AND I CHKED TO SEE IF THE ACFT WAS ON FREQ, HE WAS NOT. LOOKING BACK AT THE FL330 TFC I NOTICED Y HAD STARTED A SUBSTANTIAL L TURN. I INSTRUCTED X TO TURN 40 DEG R (RIGHT AS OR AFTER CONFLICT ALERT WAS ACTIVATED). HE ACKNOWLEDGED, I IMMEDIATELY TURNED Y 15 DEGS R. (THERE WAS NO RESPONSE, SO I EXPEDITED X DOWN TO FL310). STANDARD SEPARATION WAS LOST AT 4.56 MI 6 SECONDS BEFORE X RPTED LEVEL AT FL310. Y WAS THEN RAISED AND QUESTIONED, HE REPLIED HE WAS ON COURSE OVER LVS. 1) ON NUMEROUS OCCASIONS, ACFT HAD TO BE CALLED SEVERAL TIMES BEFORE THEY ANSWERED. 2) I THOUGHT Y WAS ASSIGNED PRESENT HDG, HE WAS NOT. 3) Y MADE ABOUT A 20 DEG L TURN ACROSS THE AIRWAY IN FRONT OF X. SUPPLEMENTAL INFO FROM ACN 303180: ACR Y CHKED IN ON NEW ZAB FREQ -- LOTS OF CHATTER ON THE FREQ. FEW MINS LATER ZAB CALLED TO ASK WHY WE HAD NOT MADE A HDG CHANGE THAT HE HAD SUPPOSEDLY GIVEN US PREVIOUSLY. NEITHER THE CAPT NOR I HAD RECEIVED OR ACKNOWLEDGED THAT DIRECTIVE FROM ATC. EVIDENTLY ANOTHER ACFT ACR X WAS GIVEN VECTORS/ALT CHANGE FOR SEPARATION INTEGRITY ON US BECAUSE OF OUR HDG/ALT. IT WAS OBVIOUS THAT THE CTLR WAS VERY BUSY WHEN WE CHKED IN ON HIS FREQ. ALSO A FLT ATTENDANT WAS IN THE COCKPIT AT THE TIME REQUESTING FLT INFO. IT IS POSSIBLE THAT THE CTLR GAVE US THE CALL BUT WE DID NOT HEAR OR ACKNOWLEDGE BECAUSE OF RADIO/FLT ATTENDANT DISTRS. AS A CREW, OUR ONLY REQUEST IS THAT IF THE CTLR DOES NOT RECEIVE AN ACKNOWLEDGEMENT FROM US THAT HE REPEAT THE COMMAND, SPEAK LOUDER TO GET OUR ATTN (IF STILL NO ACKNOWLEDGEMENT), OR ASSUME THAT WE DID NOT RECEIVE THE XMISSION AND ARE THEREFORE UNABLE TO COMPLY WITH REQUESTED FLT CHANGES.

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.