WITH SECTORS COMBINED AND INTERMITTENT EQUIP PROBS; ACR ACFT WAS DSNDED TO AN OCCUPIED ALT. CTLR TOOK EVASIVE ACTION BY CLBING THE ACFT. SECOND ACFT INVOLVED GOT A TCASII RA AND STARTED CLB ALSO. LOSS OF SEPARATION OCCURRED.

1996-03 · NASA ASRS report 332068

Date: 1996-03 · Aircraft: B737-300

Anomalies: atc-issue-all-types|conflict-airborne-conflict|deviation-discrepancy-procedural-published-material-policy|other-unspecified

Synopsis

WITH SECTORS COMBINED AND INTERMITTENT EQUIP PROBS; ACR ACFT WAS DSNDED TO AN OCCUPIED ALT. CTLR TOOK EVASIVE ACTION BY CLBING THE ACFT. SECOND ACFT INVOLVED GOT A TCASII RA AND STARTED CLB ALSO. LOSS OF SEPARATION OCCURRED.

Narrative

THE DAY OF THE INCIDENT WAS MARKED WITH CONFUSION DUE TO NUMEROUS FREQ PROBS. SEVERAL SECTORS WERE USING NON- STANDARD FREQS; INCLUDING MY SECTOR AND THE SECTOR I WAS TRYING TO COMBINE AT. THERE WERE ALSO NON-STANDARD SECTOR COMBINATIONS CREATING EVEN MORE CHAOS. MY ONLY XMITTER AND RECEIVER WERE WORKING EXTREMELY POORLY. WHEN MY PVD FAILED; THE SUPVR ADVISED TO COMBINE MY SECTOR WITH ANOTHER; NOT A NORMAL COMBINED POS. WHEN I TIRED TO BRIEF THE RADAR SIDE AT THE NEW POS; HE WAS TOO BUSY; SO I SAID FOR HIM TO CALL ME BACK WHEN READY. HIS D-SIDE CALLED ME BACK AND WAS BRIEFED MENTIONING 2 TIMES THAT ACFT Y NEEDED TO START DOWN TO MAKE HIS NORMAL RESTR FOR LNDG AT CLE. UNAWARE THAT OVER 5 MINS HAD PASSED SINCE THE COMPUTER ENTRY COMBINING SECTORS WAS MADE TO THE END OF MY BRIEFING WITH THE D-SIDE AND THAT THE RECEIVING SECTOR WAS ALREADY WORKING NEW ACFT THAT I WAS UNAWARE OF. THERE WAS FURTHER CONFUSION TAKING PLACE AFTER THE RECORDED BRIEFING. I STOOD UP AND YELLED TO THE RECEIVING SECTOR TO BE SURE TO SELECT THE CORRECT FREQS SINCE I WAS USING THE ONE FROM THE SECTOR NEXT TO ME AND THEY WERE USING MINE. THAT'S WHEN THE SUPVR TOLD ME THE NEW SECTOR COULD NOT SELECT THE CORRECT FREQ AND I WOULD HAVE TO SHIP ALL THE ACFT TO HIS FREQ. SO NOW I'M TALKING TO ALL THE ACFT AGAIN. I DSNDED ACFT Y SO HE COULD MAKE HIS NORMAL RESTR AND TOLD THE RECEIVING SECTOR. THE RADAR SIDE TOLD ME TO STOP THE ACFT AT FL270 (THE RESTR WAS FL240) BUT I HAD JUST SHIPPED THE ACFT TO HIS FREQ. I DID TRY TO RAISE THE ACFT IN CASE HE WAS STILL ON MY FREQ BUT HE DID NOT ANSWER. THE REST OF THE SCENARIO TOOK PLACE AT THE NEW SECTOR WHERE CONFUSION TOOK PART AGAIN. ACFT Y'S INITIAL CHK ON WAS BLOCKED OUT AND MISSED. WHEN HE WAS FINALLY GIVEN A CLRNC TO CLB; HE DID NOT ACKNOWLEDGE BUT WAS IN A CLB. THE NEW CTLR THEN TRIED TO DSND THE ACFT Y; AND AGAIN CLB THE ACFT BECAUSE OF THE MISCOM. ACFT X HAD BEEN DRASTICALLY TURNED; BUT ON HIS OWN CLBED OUT OF ASSIGNED ALT OF FL260 TO FL270; PUTTING THE 2 ACFT EVEN CLOSER TOGETHER. SUPPLEMENTAL INFO FROM ACN 331384: THE BFT AND SKY RADAR POS WERE JUST COMBINED AT BFT DUE TO AN EQUIP AND FREQ FAILURE AT SKY POS. ACR X; A DEP OFF CLE WAS LEVEL AT FL260. ACR Y; A CLE INBOUND WAS LEVEL AT FL290 WHEN THE POS RELIEF BRIEFING WAS ENDED AND I ASSUMED THE SKY POS. BECAUSE OF FREQ PROBS ALL DAY; I DID NOT HAVE THE ABILITY TO ASSUME THE SKY FREQ AT MY POS. THE SKY CTLR WAS ADVISED I WASN'T TALKING TO HER ACFT. ACR Y CHKED ONTO MY FREQ; DSNDING OUT OF FL270 FOR FL240. I IMMEDIATELY CLBED ACR Y BACK TO FL270 AND TURNED ACR X TO A 180 DEG HDG. ACR Y WAS CLBING BACK TO FL270 WHEN ACR X SAID HE HAD AN RA AND NEEDED TO CLB TO FL270. OPERROR DETECTION PRINTER ACTIVATED.

Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.

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