Narrative:

Widebody transport X was inbound to sfo from over alcoa. Medium large transport Y was conducting a training test flight in the air carrier southwest farallon training area at FL270. Spc Z was operating in west 260 at FL310 B330. Widebody transport X was cleared to descend to FL280 from FL390 for arrival into sfo, and to keep separated with medium large transport Y. Widebody transport X route of flight took him about 8 mi from west 260. As widebody transport X neared west 260, spc Z began to spill out of the warning area. Widebody transport X was vectored away from west 260 and spc Z vandenberg frontier control advised that they were not in contact with spc Z, that the aircraft was having navigation problems, that spc Z would return to oak center frequencys. Attempts by oak center to contact spc Z, at that time, were not successful. It appeared the widebody transport X and spc Z would come into confliction. In order for widebody transport X to continue his descent at a good rate, he was cleared down to FL240. When widebody transport X left FL290, he was clear of spc Z, but as widebody transport X approached FL280 it was realized that he would come into confliction with medium large transport Y at FL270. Widebody transport X was instructed to maintain FL280. Widebody transport X acknowledged the clearance, but his rate of descent was such that he was unable to do so and was actually already below FL280. Medium large transport Y had been on an easterly heading and was instructed to turn left to a 340 degree heading. This was to take him behind widebody transport X. These actions were not timely enough to prevent a loss of sep. The closest the aircraft came to each other was 4.2 mi latitude and 300' vertical. The required sep was 5 mi latitude or 1000' vertical, neither of which was maintained. After these 2 aircraft diverged and sep was achieved, attempts at contacting spc Z were successful and we was advised that he had spilled out of west 260. Medium large transport Y was reclred to resume his own navigation in the training area. During the loss of sep, medium large transport Y and widebody transport X were both advised of their mutual traffic. Medium large transport Y reported the widebody transport X in sight.

Google
 

Original NASA ASRS Text

Title: ARTCC CTLR HAD LESS THAN STANDARD SEPARATION WITH WDB DESCENDING THROUGH ALT OF MLG. SPC SPILLED OUT OF WARNING AREA CAUSING CTLR TO VECTOR THE WDB.

Narrative: WDB X WAS INBND TO SFO FROM OVER ALCOA. MLG Y WAS CONDUCTING A TRNING TEST FLT IN THE ACR SW FARALLON TRNING AREA AT FL270. SPC Z WAS OPERATING IN W 260 AT FL310 B330. WDB X WAS CLRED TO DSND TO FL280 FROM FL390 FOR ARR INTO SFO, AND TO KEEP SEPARATED WITH MLG Y. WDB X ROUTE OF FLT TOOK HIM ABOUT 8 MI FROM W 260. AS WDB X NEARED W 260, SPC Z BEGAN TO SPILL OUT OF THE WARNING AREA. WDB X WAS VECTORED AWAY FROM W 260 AND SPC Z VANDENBERG FRONTIER CTL ADVISED THAT THEY WERE NOT IN CONTACT WITH SPC Z, THAT THE ACFT WAS HAVING NAV PROBS, THAT SPC Z WOULD RETURN TO OAK CENTER FREQS. ATTEMPTS BY OAK CENTER TO CONTACT SPC Z, AT THAT TIME, WERE NOT SUCCESSFUL. IT APPEARED THE WDB X AND SPC Z WOULD COME INTO CONFLICTION. IN ORDER FOR WDB X TO CONTINUE HIS DSCNT AT A GOOD RATE, HE WAS CLRED DOWN TO FL240. WHEN WDB X LEFT FL290, HE WAS CLR OF SPC Z, BUT AS WDB X APCHED FL280 IT WAS REALIZED THAT HE WOULD COME INTO CONFLICTION WITH MLG Y AT FL270. WDB X WAS INSTRUCTED TO MAINTAIN FL280. WDB X ACKNOWLEDGED THE CLRNC, BUT HIS RATE OF DSCNT WAS SUCH THAT HE WAS UNABLE TO DO SO AND WAS ACTUALLY ALREADY BELOW FL280. MLG Y HAD BEEN ON AN EASTERLY HDG AND WAS INSTRUCTED TO TURN LEFT TO A 340 DEG HDG. THIS WAS TO TAKE HIM BEHIND WDB X. THESE ACTIONS WERE NOT TIMELY ENOUGH TO PREVENT A LOSS OF SEP. THE CLOSEST THE ACFT CAME TO EACH OTHER WAS 4.2 MI LAT AND 300' VERT. THE REQUIRED SEP WAS 5 MI LAT OR 1000' VERT, NEITHER OF WHICH WAS MAINTAINED. AFTER THESE 2 ACFT DIVERGED AND SEP WAS ACHIEVED, ATTEMPTS AT CONTACTING SPC Z WERE SUCCESSFUL AND WE WAS ADVISED THAT HE HAD SPILLED OUT OF W 260. MLG Y WAS RECLRED TO RESUME HIS OWN NAV IN THE TRNING AREA. DURING THE LOSS OF SEP, MLG Y AND WDB X WERE BOTH ADVISED OF THEIR MUTUAL TFC. MLG Y RPTED THE WDB X IN SIGHT.

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.