Narrative:

I was the first officer and PNF en route from pittsburgh to cincinnati (cvg). We were cruising wbound at our assigned altitude of FL220 about 10 mi east of ape VOR on cleveland center frequency of 124.45. At this point we received a TCASII TA (traffic advisory) 'traffic, traffic'. We observed on the TCASII a yellow traffic symbol 12 O'clock, approximately 5 mi, 1200 ft above us and descending. A few seconds later it showed 1100 ft above and descending, then 1000 ft above and descending and then at 900 ft above and descending the symbol turned red and we received a TCASII RA 'descend, descend!' we received the descend voice command and a descend on the vertical speed indicator with red light down to -2000 FPM and then a green arc at about -2000 FPM to -2500 FPM. At this point the captain immediately disconnected the autoplt and descended in the green arc on the vertical speed indicator. I immediately reported to cle center 'company identify TCASII descent!' during the descent we observed an aircraft large transport pass from left to right a few mi in front of us. After we notified cle center of our descent, cle center called air carrier Y and asked them their altitude. Air carrier Y then reported that they were in a TCASII descent and leveling at 220. As we descended to about FL210 TCASII gave us 'clear of conflict'. At this point and after some confusion between cle center and air carrier Y cle center told us to descend to FL200 and air carrier Y to descend to FL210. In the conversation between cle center and air carrier Y cle told air carrier Y that they were assigned FL230 and air carrier Y reported that their TCASII told them to descend so they did. So air carrier Y's TCASII descent caused a conflict for us and thence our TCASII gave us an RA descent. As a note, cle center confirmed that controller training was in progress. The remainder of the flight proceeded normally.

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Original NASA ASRS Text

Title: ACR MLG ALTDEV EXCURSION FROM CLRNC ALT IN RESPONSE TO TCASII RA. TCASII TFC WAS A SECOND ACR LGT THAT WAS RESPONDING TO THEIR OWN TCASII RA FROM UNIDENTED TFC.

Narrative: I WAS THE FO AND PNF ENRTE FROM PITTSBURGH TO CINCINNATI (CVG). WE WERE CRUISING WBOUND AT OUR ASSIGNED ALT OF FL220 ABOUT 10 MI E OF APE VOR ON CLEVELAND CENTER FREQ OF 124.45. AT THIS POINT WE RECEIVED A TCASII TA (TFC ADVISORY) 'TFC, TFC'. WE OBSERVED ON THE TCASII A YELLOW TFC SYMBOL 12 O'CLOCK, APPROX 5 MI, 1200 FT ABOVE US AND DSNDING. A FEW SECONDS LATER IT SHOWED 1100 FT ABOVE AND DSNDING, THEN 1000 FT ABOVE AND DSNDING AND THEN AT 900 FT ABOVE AND DSNDING THE SYMBOL TURNED RED AND WE RECEIVED A TCASII RA 'DSND, DSND!' WE RECEIVED THE DSND VOICE COMMAND AND A DSND ON THE VERT SPD INDICATOR WITH RED LIGHT DOWN TO -2000 FPM AND THEN A GREEN ARC AT ABOUT -2000 FPM TO -2500 FPM. AT THIS POINT THE CAPT IMMEDIATELY DISCONNECTED THE AUTOPLT AND DSNDED IN THE GREEN ARC ON THE VERT SPD INDICATOR. I IMMEDIATELY RPTED TO CLE CENTER 'COMPANY IDENT TCASII DSCNT!' DURING THE DSCNT WE OBSERVED AN ACFT LGT PASS FROM L TO R A FEW MI IN FRONT OF US. AFTER WE NOTIFIED CLE CENTER OF OUR DSCNT, CLE CENTER CALLED ACR Y AND ASKED THEM THEIR ALT. ACR Y THEN RPTED THAT THEY WERE IN A TCASII DSCNT AND LEVELING AT 220. AS WE DSNDED TO ABOUT FL210 TCASII GAVE US 'CLR OF CONFLICT'. AT THIS POINT AND AFTER SOME CONFUSION BTWN CLE CENTER AND ACR Y CLE CENTER TOLD US TO DSND TO FL200 AND ACR Y TO DSND TO FL210. IN THE CONVERSATION BTWN CLE CENTER AND ACR Y CLE TOLD ACR Y THAT THEY WERE ASSIGNED FL230 AND ACR Y RPTED THAT THEIR TCASII TOLD THEM TO DSND SO THEY DID. SO ACR Y'S TCASII DSCNT CAUSED A CONFLICT FOR US AND THENCE OUR TCASII GAVE US AN RA DSCNT. AS A NOTE, CLE CENTER CONFIRMED THAT CTLR TRAINING WAS IN PROGRESS. THE REMAINDER OF THE FLT PROCEEDED NORMALLY.

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.