Narrative:

2 aircraft in the sector above ours were being vectored and descended. Aircraft X came on our frequency reporting level at FL270. I did not hear this due to being busy with my d-side duties. When I looked at the radar, I noticed the data block showed FL270 descending to FL240. The radar controller did not ask me to coordinate for lower with the previous controller, so I did not know that he was level at FL270 and not in a descent. I then overheard the previous radar controller call the radar controller at my sector and ask him to push aircraft #1 down. The radar controller attempted to do so, calling the aircraft several times with a descent clearance, but aircraft #1 would not answer. When the aircraft did answer, he stated he was responding to a TCASII RA and was climbing. At virtually the same time the conflict alert activated showing another aircraft at FL270. I immediately notified the previous radar controller of the TCASII RA response and that the aircraft was climbing. Supplemental information from acn 422864: aircraft #1 had been vectored for in trail spacing. He had also been stepped down on altitude because of other traffic. Aircraft #1 was given a heading for the dxo 147 degree radial and descended from FL270 to FL240, assigned an airspeed and communications xfer to frequency 127.9. Aircraft #2 at FL280 was given descent to FL270 to start descent into day. Aircraft #1 checked in and the call sign had to be verified. I noticed aircraft #1 had not descended to FL240. Called crl control position to get aircraft #1 'pushed' down. Crl d-side called to say aircraft #1 had an RA and was climbing. Aircraft #2 was assigned FL280, heading, then descended to FL260. Several aircraft had to be reissued clrncs. Supplemental information from acn 422865: aircraft #1 was given a descent clearance and a turn. Aircraft #1 read back the turn but not the descent. Aircraft #1 continued to fly at that altitude for 20 mi. With only 15 mi to the intersection that the aircraft had to cross at 12000 ft (on approach plate), I would have thought the pilot would have asked for lower.

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Original NASA ASRS Text

Title: ZOB RADAR CTLR ISSUES DSCNT CLRNC TO A320 AND XFERS COM TO THE NEXT SECTOR, THEN DSNDS A DC8 TO THE EXPECTED VACATED ALT. THE A320 DOES NOT DSND INITIALLY AND WHEN IT DOES, INITIATES A TCASII CLB BACK TO PREVIOUS ALT, CONFLICTING WITH DSNDING DC8.

Narrative: 2 ACFT IN THE SECTOR ABOVE OURS WERE BEING VECTORED AND DSNDED. ACFT X CAME ON OUR FREQ RPTING LEVEL AT FL270. I DID NOT HEAR THIS DUE TO BEING BUSY WITH MY D-SIDE DUTIES. WHEN I LOOKED AT THE RADAR, I NOTICED THE DATA BLOCK SHOWED FL270 DSNDING TO FL240. THE RADAR CTLR DID NOT ASK ME TO COORDINATE FOR LOWER WITH THE PREVIOUS CTLR, SO I DID NOT KNOW THAT HE WAS LEVEL AT FL270 AND NOT IN A DSCNT. I THEN OVERHEARD THE PREVIOUS RADAR CTLR CALL THE RADAR CTLR AT MY SECTOR AND ASK HIM TO PUSH ACFT #1 DOWN. THE RADAR CTLR ATTEMPTED TO DO SO, CALLING THE ACFT SEVERAL TIMES WITH A DSCNT CLRNC, BUT ACFT #1 WOULD NOT ANSWER. WHEN THE ACFT DID ANSWER, HE STATED HE WAS RESPONDING TO A TCASII RA AND WAS CLBING. AT VIRTUALLY THE SAME TIME THE CONFLICT ALERT ACTIVATED SHOWING ANOTHER ACFT AT FL270. I IMMEDIATELY NOTIFIED THE PREVIOUS RADAR CTLR OF THE TCASII RA RESPONSE AND THAT THE ACFT WAS CLBING. SUPPLEMENTAL INFO FROM ACN 422864: ACFT #1 HAD BEEN VECTORED FOR IN TRAIL SPACING. HE HAD ALSO BEEN STEPPED DOWN ON ALT BECAUSE OF OTHER TFC. ACFT #1 WAS GIVEN A HDG FOR THE DXO 147 DEG RADIAL AND DSNDED FROM FL270 TO FL240, ASSIGNED AN AIRSPD AND COMS XFER TO FREQ 127.9. ACFT #2 AT FL280 WAS GIVEN DSCNT TO FL270 TO START DSCNT INTO DAY. ACFT #1 CHKED IN AND THE CALL SIGN HAD TO BE VERIFIED. I NOTICED ACFT #1 HAD NOT DSNDED TO FL240. CALLED CRL CTL POS TO GET ACFT #1 'PUSHED' DOWN. CRL D-SIDE CALLED TO SAY ACFT #1 HAD AN RA AND WAS CLBING. ACFT #2 WAS ASSIGNED FL280, HDG, THEN DSNDED TO FL260. SEVERAL ACFT HAD TO BE REISSUED CLRNCS. SUPPLEMENTAL INFO FROM ACN 422865: ACFT #1 WAS GIVEN A DSCNT CLRNC AND A TURN. ACFT #1 READ BACK THE TURN BUT NOT THE DSCNT. ACFT #1 CONTINUED TO FLY AT THAT ALT FOR 20 MI. WITH ONLY 15 MI TO THE INTXN THAT THE ACFT HAD TO CROSS AT 12000 FT (ON APCH PLATE), I WOULD HAVE THOUGHT THE PLT WOULD HAVE ASKED FOR LOWER.

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.