Narrative:

ZDC (sector 59 sea isle hi) was operating smoothly at approximately xa:17 pm. At that moment I had 6 aircraft to be descended to FL210 to be handed off to ZNY center at FL210 inbound to isp and bdr. The first two, (including large transport X) were approaching the ZNY boundary in handoff status. At that moment, ZNY advised (spin em)! Cannot take any more traffic. Large transport X and a navy aircraft were tracking nebound on V139-now issued clearance by me, turn right heading 235 degree, and explained why. Then started giving clrncs to stop the other 4 aircraft behind those two. Considering other traffic that got involved with these aircraft descending and spinning, the sector started a downhill slide fast. At this point the sector that stopped the traffic (ZNY sector 66), called with a manual handoff involving a limited data tag. (No information in computer.) I was now extremely busy and told the sector to (keep them coming) while I put the 'D' side on to copy the flight plan information. At this point I asked for and received a 'handoff man' to help out. I moved over to the 'right position only' and continued with urgent priorities to keep aircraft separated. In doing this, I neglected to tell the new handoff position man to start TA track on the limited data aircraft that was continuing wbound from ZNY at FL230. This traffic (light transport Y) was supposed to travel J174 toward swl VORTAC. I don't know why yet, but somehow light transport Y proceeded toward sie along J121, hidden under my full data blocks spinning along J121. I finally get back to large transport X (still heading 235 degree southeast of sie VORTAC) I turned him right to a 010 degree heading to intercept V139 and cleared him to the 30 mi DME fix northeast of sie. Moments later as large transport X was approaching V139, (also J121), I noticed a limited data tag showing FL230 that appeared out from under several full data blocks. This limited data tag was approximately 5 miles - almost headon with large transport X also at FL230. The frequency was extremely congested with traffic trying to talk to me, so I instantly transmitted (large transport X descend immediately to FL220, large transport X descend immediately to FL220). Iissued the clearance twice just in case my initial transmission might be blocked. As I started my transmission, the radar up-dated to 2 1/2 mi. As I finished transmitting, large transport X responded by saying that he had the traffic in sight and everything was ok. The targets then merged showing FL223 on large transport X and FL230 on light transport Y. I guess that the main contributing factor here was the extremely quick explosion from light traffic to extremely busy, plus moving from radar and handoff position to radar position with a new controller in the handoff position causing me to forget about a full data block on light transport Y. Also, light transport Y proceeding along the wrong route causing his limited data tag to be obscured within the full data blocks of the traffic on J121. The last item, light transport Y never called on the frequency. If he had, it would have been the reminder of his flight. On human performance, normally a handoff man is provided prior to the sector reached extremely heavy conditions. This time, it was almost instantaneous, from the moment traffic was when a controller plugs into a sector to help out, it takes a few moments to figure hat is going on and to get priorities in order. This time the 'left' side never had a chance to get oriented until the incident. After that he was fine. At this point another ZNY sector (67) stopped traffic on us involving jfk inbounds, and we had to stop these aircraft. These aircraft were already on vectors to avoid the other holding aircraft. The next 20 minutes were interesting to say the least, until the traffic was finally moved on, and the sector cleared up. 'Sure would be great if our computer system could 'conflict alert' with a limited data altitude!'. Supplemental information from acn #87756: other aircraft believed to be an light transport Y cruising through our holding pattern at our altitude - we were issued an immediate descent by ATC and visually spotted the light transport Y at that time... We were in a turn in holding pattern so continued the turn and descended to avoid conflict - he was no radio at the time, we were being held by ZDC. Possible contributing factor was confusion on radio with repeated xmissions to clarify holding instructions given with short notice. Solutions include simplifying cockpit procedures so we can look outside more. Reducing ATC workload. Conflict alert expansion of buffer zone. In-flight collision avoidance hardware in cockpit. Supplemental information from acn #87841: we saw the intruder aircraft about 2 NM away and tightened our right holding turn to miss him while beginning a descent at the controllers request.

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Original NASA ASRS Text

Title: LESS THAN STANDARD SEPARATION BETWEEN LGT IN HOLDING PATTERN AND LTT ENROUTE AT SAME ALT. HEAVY TRAFFIC OPERATIONAL ERROR.

Narrative: ZDC (SECTOR 59 SEA ISLE HI) WAS OPERATING SMOOTHLY AT APPROX XA:17 PM. AT THAT MOMENT I HAD 6 ACFT TO BE DESCENDED TO FL210 TO BE HANDED OFF TO ZNY CENTER AT FL210 INBOUND TO ISP AND BDR. THE FIRST TWO, (INCLUDING LGT X) WERE APCHING THE ZNY BOUNDARY IN HANDOFF STATUS. AT THAT MOMENT, ZNY ADVISED (SPIN EM)! CANNOT TAKE ANY MORE TFC. LGT X AND A NAVY ACFT WERE TRACKING NEBOUND ON V139-NOW ISSUED CLRNC BY ME, TURN RIGHT HEADING 235 DEG, AND EXPLAINED WHY. THEN STARTED GIVING CLRNCS TO STOP THE OTHER 4 ACFT BEHIND THOSE TWO. CONSIDERING OTHER TFC THAT GOT INVOLVED WITH THESE ACFT DESCENDING AND SPINNING, THE SECTOR STARTED A DOWNHILL SLIDE FAST. AT THIS POINT THE SECTOR THAT STOPPED THE TFC (ZNY SECTOR 66), CALLED WITH A MANUAL HANDOFF INVOLVING A LIMITED DATA TAG. (NO INFO IN COMPUTER.) I WAS NOW EXTREMELY BUSY AND TOLD THE SECTOR TO (KEEP THEM COMING) WHILE I PUT THE 'D' SIDE ON TO COPY THE FLT PLAN INFO. AT THIS POINT I ASKED FOR AND RECEIVED A 'HANDOFF MAN' TO HELP OUT. I MOVED OVER TO THE 'R POSITION ONLY' AND CONTINUED WITH URGENT PRIORITIES TO KEEP ACFT SEPARATED. IN DOING THIS, I NEGLECTED TO TELL THE NEW HANDOFF POSITION MAN TO START TA TRACK ON THE LIMITED DATA ACFT THAT WAS CONTINUING WBOUND FROM ZNY AT FL230. THIS TFC (LTT Y) WAS SUPPOSED TO TRAVEL J174 TOWARD SWL VORTAC. I DON'T KNOW WHY YET, BUT SOMEHOW LTT Y PROCEEDED TOWARD SIE ALONG J121, HIDDEN UNDER MY FULL DATA BLOCKS SPINNING ALONG J121. I FINALLY GET BACK TO LGT X (STILL HEADING 235 DEG SE OF SIE VORTAC) I TURNED HIM RIGHT TO A 010 DEG HDG TO INTERCEPT V139 AND CLRED HIM TO THE 30 MI DME FIX NE OF SIE. MOMENTS LATER AS LGT X WAS APCHING V139, (ALSO J121), I NOTICED A LIMITED DATA TAG SHOWING FL230 THAT APPEARED OUT FROM UNDER SEVERAL FULL DATA BLOCKS. THIS LIMITED DATA TAG WAS APPROX 5 MILES - ALMOST HEADON WITH LGT X ALSO AT FL230. THE FREQ WAS EXTREMELY CONGESTED WITH TFC TRYING TO TALK TO ME, SO I INSTANTLY TRANSMITTED (LGT X DESCEND IMMEDIATELY TO FL220, LGT X DESCEND IMMEDIATELY TO FL220). IISSUED THE CLRNC TWICE JUST IN CASE MY INITIAL XMISSION MIGHT BE BLOCKED. AS I STARTED MY XMISSION, THE RADAR UP-DATED TO 2 1/2 MI. AS I FINISHED TRANSMITTING, LGT X RESPONDED BY SAYING THAT HE HAD THE TFC IN SIGHT AND EVERYTHING WAS OK. THE TARGETS THEN MERGED SHOWING FL223 ON LGT X AND FL230 ON LTT Y. I GUESS THAT THE MAIN CONTRIBUTING FACTOR HERE WAS THE EXTREMELY QUICK EXPLOSION FROM LIGHT TFC TO EXTREMELY BUSY, PLUS MOVING FROM RADAR AND HDOF POSITION TO RADAR POSITION WITH A NEW CTLR IN THE HDOF POSITION CAUSING ME TO FORGET ABOUT A FULL DATA BLOCK ON LTT Y. ALSO, LTT Y PROCEEDING ALONG THE WRONG ROUTE CAUSING HIS LIMITED DATA TAG TO BE OBSCURED WITHIN THE FULL DATA BLOCKS OF THE TFC ON J121. THE LAST ITEM, LTT Y NEVER CALLED ON THE FREQ. IF HE HAD, IT WOULD HAVE BEEN THE REMINDER OF HIS FLT. ON HUMAN PERFORMANCE, NORMALLY A HANDOFF MAN IS PROVIDED PRIOR TO THE SECTOR REACHED EXTREMELY HEAVY CONDITIONS. THIS TIME, IT WAS ALMOST INSTANTANEOUS, FROM THE MOMENT TFC WAS WHEN A CTLR PLUGS INTO A SECTOR TO HELP OUT, IT TAKES A FEW MOMENTS TO FIGURE HAT IS GOING ON AND TO GET PRIORITIES IN ORDER. THIS TIME THE 'L' SIDE NEVER HAD A CHANCE TO GET ORIENTED UNTIL THE INCIDENT. AFTER THAT HE WAS FINE. AT THIS POINT ANOTHER ZNY SECTOR (67) STOPPED TFC ON US INVOLVING JFK INBOUNDS, AND WE HAD TO STOP THESE ACFT. THESE ACFT WERE ALREADY ON VECTORS TO AVOID THE OTHER HOLDING ACFT. THE NEXT 20 MINUTES WERE INTERESTING TO SAY THE LEAST, UNTIL THE TFC WAS FINALLY MOVED ON, AND THE SECTOR CLRED UP. 'SURE WOULD BE GREAT IF OUR COMPUTER SYSTEM COULD 'CONFLICT ALERT' WITH A LIMITED DATA ALT!'. SUPPLEMENTAL INFORMATION FROM ACN #87756: OTHER ACFT BELIEVED TO BE AN LTT Y CRUISING THROUGH OUR HOLDING PATTERN AT OUR ALT - WE WERE ISSUED AN IMMEDIATE DESCENT BY ATC AND VISUALLY SPOTTED THE LTT Y AT THAT TIME... WE WERE IN A TURN IN HOLDING PATTERN SO CONTINUED THE TURN AND DESCENDED TO AVOID CONFLICT - HE WAS NO RADIO AT THE TIME, WE WERE BEING HELD BY ZDC. POSSIBLE CONTRIBUTING FACTOR WAS CONFUSION ON RADIO WITH REPEATED XMISSIONS TO CLARIFY HOLDING INSTRUCTIONS GIVEN WITH SHORT NOTICE. SOLUTIONS INCLUDE SIMPLIFYING COCKPIT PROCEDURES SO WE CAN LOOK OUTSIDE MORE. REDUCING ATC WORKLOAD. CONFLICT ALERT EXPANSION OF BUFFER ZONE. IN-FLT COLLISION AVOIDANCE HARDWARE IN COCKPIT. SUPPLEMENTAL INFORMATION FROM ACN #87841: WE SAW THE INTRUDER ACFT ABOUT 2 NM AWAY AND TIGHTENED OUR RIGHT HOLDING TURN TO MISS HIM WHILE BEGINNING A DESCENT AT THE CTLRS REQUEST.

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.