Narrative:

Air carrier X departed mia going swbound over canoa. Air carrier Y was nebound about 15 mi southeast of canoa. Air carrier X was about 25 mi northeast of canoa intersection climbing to FL350 leaving FL333 in a very slow climb. For ATC separation at that altitude I need 2000 ft and 5 mi, so I turned the air carrier X to a heading of 270 degrees and told the aircraft to expedite to FL350. At this time, air carrier X climbed almost 1200 ft, then stopped his clt at FL345 and told me he had air carrier Y on TCASII and for the next min leveled off at altitude. 3 times, the aircraft was told to climb to FL350 and each time the pilot replied he had the aircraft on TCASII. After the third time, we had insufficient separation. The only way to solve this problem is to get the pilots to understand that they cannot use TCASII to separate themselves. Callback conversation with reporter revealed the following information: reporter experience 7 yrs radar, 8 yrs military. Separation was 3.3 mi, 1400 ft. Controller training was in progress and the reporter instructor had taken over control of the position from the trainee. The reporter believes the air carrier X was using TCASII to separate themselves from air carrier Y. Also, reporter thinks air carrier X turned off mode C because after the 3 hits at FL345 he did not receive mode C altitude until the aircraft was level FL350. FAA investigation downgraded the incident to a non-event. Supplemental information from acn 228094: air carrier X was issued a heading and an expeditious climb to FL350. The air carrier X was 30 mi from his traffic out of FL330 to FL350 at the time the clearance was issued. In 1 min, air carrier X was at FL345 and he appeared to have leveled off. When asked to verify reaching FL350, he responded, negative we're at FL345 and we have traffic on our TCASII. I believe that the pilot was using TCASII as a means of separation and not conforming to the clearance issued.

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Original NASA ASRS Text

Title: ACR X NON ADHERENCE TO ATC CLRNC UNDERSHOOT ASSIGNED ALT HAD LTSS FROM ACR Y.

Narrative: ACR X DEPARTED MIA GOING SWBOUND OVER CANOA. ACR Y WAS NEBOUND ABOUT 15 MI SE OF CANOA. ACR X WAS ABOUT 25 MI NE OF CANOA INTXN CLBING TO FL350 LEAVING FL333 IN A VERY SLOW CLB. FOR ATC SEPARATION AT THAT ALT I NEED 2000 FT AND 5 MI, SO I TURNED THE ACR X TO A HDG OF 270 DEGS AND TOLD THE ACFT TO EXPEDITE TO FL350. AT THIS TIME, ACR X CLBED ALMOST 1200 FT, THEN STOPPED HIS CLT AT FL345 AND TOLD ME HE HAD ACR Y ON TCASII AND FOR THE NEXT MIN LEVELED OFF AT ALT. 3 TIMES, THE ACFT WAS TOLD TO CLB TO FL350 AND EACH TIME THE PLT REPLIED HE HAD THE ACFT ON TCASII. AFTER THE THIRD TIME, WE HAD INSUFFICIENT SEPARATION. THE ONLY WAY TO SOLVE THIS PROBLEM IS TO GET THE PLTS TO UNDERSTAND THAT THEY CANNOT USE TCASII TO SEPARATE THEMSELVES. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR EXPERIENCE 7 YRS RADAR, 8 YRS MIL. SEPARATION WAS 3.3 MI, 1400 FT. CTLR TRAINING WAS IN PROGRESS AND THE RPTR INSTRUCTOR HAD TAKEN OVER CTL OF THE POS FROM THE TRAINEE. THE RPTR BELIEVES THE ACR X WAS USING TCASII TO SEPARATE THEMSELVES FROM ACR Y. ALSO, RPTR THINKS ACR X TURNED OFF MODE C BECAUSE AFTER THE 3 HITS AT FL345 HE DID NOT RECEIVE MODE C ALT UNTIL THE ACFT WAS LEVEL FL350. FAA INVESTIGATION DOWNGRADED THE INCIDENT TO A NON-EVENT. SUPPLEMENTAL INFO FROM ACN 228094: ACR X WAS ISSUED A HDG AND AN EXPEDITIOUS CLB TO FL350. THE ACR X WAS 30 MI FROM HIS TFC OUT OF FL330 TO FL350 AT THE TIME THE CLRNC WAS ISSUED. IN 1 MIN, ACR X WAS AT FL345 AND HE APPEARED TO HAVE LEVELED OFF. WHEN ASKED TO VERIFY REACHING FL350, HE RESPONDED, NEGATIVE WE'RE AT FL345 AND WE HAVE TFC ON OUR TCASII. I BELIEVE THAT THE PLT WAS USING TCASII AS A MEANS OF SEPARATION AND NOT CONFORMING TO THE CLRNC ISSUED.

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.