LOSS OF TFC SEPARATION N OF GSO; NC.

Narrative

ZDC CLRED US TO FL350 AND SHORTLY AFTER CLRED US TO FL330. BEFORE LEVELING FL330; WE WERE GIVEN ANOTHER DSCNT TO FL290. SHORTLY AFTER THE CLRNC TO FL290; ZDC DIRECTED US TO INCREASE OUR RATE OF DSCNT. WHILE DSNDING AT 2000 FPM; ZDC DIRECTED US TO USE BEST RATE; AND ONCE THROUGH FL290 TURN L HDG 050 DEGS. OUR INSTRUCTIONS WERE CONFUSING BECAUSE WE WERE ASKED TO USE BEST RATE OF DSCNT AND WE ONLY HAD TO LOSE 3000-4000 FT. BECAUSE OF THE URGENCY WITH WHICH ZDC WAS TAKING US DOWN; I RECALL NOTING THERE MUST BE A TFC CONFLICT; SO WE NEEDED TO COMPLY WITH THE INSTRUCTIONS AND INCREASE OUR DSCNT RATE. AT APPROX FL290; I SPOTTED AN ACFT Y; DC9; IN OUR 10 O'CLOCK POS MOVING TO 12 O'CLOCK POS. AS WE WERE NEVER INSTRUCTED TO LOOK FOR TFC; MY COPLT AND I WERE SHOCKED. ASSUMING OUR PREVIOUS INSTRUCTIONS TO INCREASE RATE OF DSCNT WERE NEEDED TO RESOLVE A CONFLICT WITH THE DC9; I TOOK EVASIVE MEASURES AND DSNDED BELOW THE TFC. ONCE CLR OF THE TFC; I QUERIED MY COPLT ABOUT OUR ASSIGNED ALT; WHICH HE THOUGHT WAS FL290. WE WERE BTWN FL260 AND FL270 SO I CLBED WITHOUT DELAY TO FL290. SUPPLEMENTAL INFO FROM ACN 477180: IT IS MY OPINION THAT HAD WE SEEN THE DC9 EARLIER; WE MIGHT NOT HAVE HAD TO RESORT TO SUCH EXTREME MANEUVERS TO AVOID THE ACFT. (WE POSSIBLY COULD HAVE REDUCED OUR RATE OF DSCNT OR CHANGED HDG.) WE DID NOT SEE THE DC9 UNTIL IT EMERGED FROM BEHIND CLOUDS THAT WERE BTWN US THE DC9. IF WE WERE ADVISED ABOUT POSSIBLE TFC BY ATC; THIS COULD HAVE ALSO HELPED THE SIT. SUPPLEMENTAL INFO FROM ACN 478316: I WAS WORKING A HIGH ALT ENRTE SECTOR WITH WX AFFECTING ABOUT 20% OF THE SECTOR AND ACFT DEVIATING OFF THEIR ASSIGNED RTES. A LEAR 23 (ACFT X) WAS ABOVE OTHER TFC AND NEEDED TO BE DSNDED SINCE HIS DEST WAS NEARBY. I PLACED THE LEAR ON A HDG AND ASSIGNED HIM AN ALT OF FL290 AND ASKED HIM FOR HIS BEST RATE OF DSCNT. HE ACKNOWLEDGED FOR THE HDG AND THE CORRECT ALT. HE WAS DSNDING IN THE VICINITY OF A DC9 AT FL280. THE DC9 RPTED A LEARJET DSNDING THROUGH HIS ALT AND ASKED IF WE WERE WORKING THAT ACFT. I REPLIED THAT HE SHOULD BE AT FL290 AND ASKED THE LEAR TO SAY HIS ALT. THE LEAR SAID HE WAS AT FL290. THE LEAR ALSO SAID THE PROX OF THE ACFT SEEMED CLOSE. THE DC9 LATER REITERATED THAT THE LEARJET WAS BELOW HIS ALT.