Narrative:

Flight to phx was approximately 30 mi east of trm (thermal VOR) passing through FL240 to our filed altitude of FL250 when a 'cargo door' caution message illuminated on our ED1 along with the associated master caution warning indication. First officer was the PF and I was the PNF. As soon as the 'cargo door' caution message illuminated, our 'attention' was immediately drawn to that particular task. Approximately 10 seconds after the 'cargo door' caution message illuminated, and passing through FL245, we received a TCASII RA of a target at our 10 O'clock position and within approximately 2 mi of our present position indicating FL245. This particular target was not observed prior to the conflict, although the TCASII immediately recognized the threat at the time it appeared on our mfd 1/2 and commanded a 'descend, descend.' at this point, I slewed my range knob to display the 2.5/5 mi ring (range) on my mfd 1 and reverified the range of the RA conflict in relation to our aircraft. The range of the RA was inside approximately 2 mi and indicating FL245. Immediately after being commanded to 'descend, descend,' first officer disconnected the autoplt and proceeded to initiate an approximately 2000 FPM descent as instructed by the TCASII RA. I immediately contacted ATC and informed them we were deviating from our altitude and descending due to an RA. At the same time, another airline jet was trailing our aircraft by approximately 2 mi at an approximately altitude of FL240. As we initiated our mandatory descent due to the RA conflict of the aircraft target at FL245, our flight began to encroach into the flight path of the trailing jet, which was directly behind us, and a second RA was recognized by the TCASII. At this point in time, we had two targets -- one at our 10 O'clock position at FL245 and the jet at our 6 O'clock position at FL240 -- both aircraft were within a range of 2 mi as depicted on our mfd 1/2. It is also noteworthy to add, as we descended into the flight path of the jet, and the second RA was triggered, the TCASII RA seemed to get 'confused' with one RA target being higher and one RA target being lower. The system initially commanded to 'descend' and within a few seconds later commanded a 'climb' per the RA. As we were descending per the RA, I commanded first officer to stop the descent of our aircraft at FL240 because I could see our aircraft was encroaching into the same altitude as the jet. As we leveled the aircraft at FL240, I noticed the subject jet had descended to FL235 as depicted on my mfd 1. At some time, ATC acknowledged the receipt of our deviation in altitude and vectored the jet away from our flight path. Seconds later, the RA of the 10 O'clock position traffic had disappeared from our mfd 1/2. I visually scanned the area for any threat and then commanded first officer to climb back up to FL250 (our filed altitude) to allow better separation of our aircraft from the jet. Once again, as we began to climb through FL245, the RA traffic reappeared on our mfd 1/2 and an immediate RA was commanded by the TCASII to 'descend, descend' which we followed to an altitude of FL240. No target at our 2 O'clock was visually found. ATC then inquired about our deviation and we were cleared back to our original altitude. As flight landed in phx, ground control informed us that ATC center wanted to talk to us and relayed the phone number. I was to ask for mr X. Upon arrival at the gate, and as the passenger were deplaning, I then called mr X and explained in detail what had just happened. Mr X understood that we observed an RA and we performed the necessary maneuver to eliminate the conflict, but mr X was concerned about our actions because our flight path caused a conflict with the trailing jet. Mr X seemed highly agitated and informed me 'at no time was there any air traffic at FL245 and at no time was there any air traffic in conflict to our aircraft as we were climbing to FL250.' I assured mr X that I'm quite sure that 'he' observed no potential traffic conflict as we were climbing to our assigned flight level of FL250. Nevertheless, I explained to mr X that his statement was irrelevant because our TCASII commanded an RA in which I explained to him was mandatory for our crew to comply. The conflict that we caused in regards to the jet, in myopinion, was circumstance. It is also in my opinion that the jet was allowed to be 'too close' in trail of our aircraft during our climb. Mr X strongly suggested to have our TCASII system inspected because of the obvious erroneous TCASII RA. I agreed. Mr X then relayed to me that it was no fault of our crew and he was going to document the incident as a 'TCASII incident.' after I got off the phone with mr X I then called the maintenance operations director, and relayed to him the sequence of events. I advised him of the erroneous indication that the TCASII produced and the potential disastrous outcome that was avoided in regards to the near miss of the jet. Mr X informed me that our aircraft at one point, came within 1 1/4 mi and within 700 ft of the jet. Supplemental information from acn 585823: the first and third RA's were for an aircraft showing on our TCASII displays at our 10 O'clock position and about 10 mi. Upon talking with ATC, both after the incident and later by phone on the ground, we learned that there was no aircraft in that area at the time. This is why the controller seemed in disbelief that we were descending per the RA.

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Original NASA ASRS Text

Title: A CLBING CL-65 FLT RECEIVES A TCASII RA FOR A SUPPOSED ACFT AT THEIR ALT. WHILE DSNDING PER TCASII COMMANDS, THEY INTRUDE INTO THE AIRSPACE OF ANOTHER AIRLINE'S TRAILING JET, REQUIRING THEIR JET TO DSND ON THEIR TCASII RA, 30 MI E OF TRM, CA.

Narrative: FLT TO PHX WAS APPROX 30 MI E OF TRM (THERMAL VOR) PASSING THROUGH FL240 TO OUR FILED ALT OF FL250 WHEN A 'CARGO DOOR' CAUTION MESSAGE ILLUMINATED ON OUR ED1 ALONG WITH THE ASSOCIATED MASTER CAUTION WARNING INDICATION. FO WAS THE PF AND I WAS THE PNF. AS SOON AS THE 'CARGO DOOR' CAUTION MESSAGE ILLUMINATED, OUR 'ATTN' WAS IMMEDIATELY DRAWN TO THAT PARTICULAR TASK. APPROX 10 SECONDS AFTER THE 'CARGO DOOR' CAUTION MESSAGE ILLUMINATED, AND PASSING THROUGH FL245, WE RECEIVED A TCASII RA OF A TARGET AT OUR 10 O'CLOCK POS AND WITHIN APPROX 2 MI OF OUR PRESENT POS INDICATING FL245. THIS PARTICULAR TARGET WAS NOT OBSERVED PRIOR TO THE CONFLICT, ALTHOUGH THE TCASII IMMEDIATELY RECOGNIZED THE THREAT AT THE TIME IT APPEARED ON OUR MFD 1/2 AND COMMANDED A 'DSND, DSND.' AT THIS POINT, I SLEWED MY RANGE KNOB TO DISPLAY THE 2.5/5 MI RING (RANGE) ON MY MFD 1 AND REVERIFIED THE RANGE OF THE RA CONFLICT IN RELATION TO OUR ACFT. THE RANGE OF THE RA WAS INSIDE APPROX 2 MI AND INDICATING FL245. IMMEDIATELY AFTER BEING COMMANDED TO 'DSND, DSND,' FO DISCONNECTED THE AUTOPLT AND PROCEEDED TO INITIATE AN APPROX 2000 FPM DSCNT AS INSTRUCTED BY THE TCASII RA. I IMMEDIATELY CONTACTED ATC AND INFORMED THEM WE WERE DEVIATING FROM OUR ALT AND DSNDING DUE TO AN RA. AT THE SAME TIME, ANOTHER AIRLINE JET WAS TRAILING OUR ACFT BY APPROX 2 MI AT AN APPROX ALT OF FL240. AS WE INITIATED OUR MANDATORY DSCNT DUE TO THE RA CONFLICT OF THE ACFT TARGET AT FL245, OUR FLT BEGAN TO ENCROACH INTO THE FLT PATH OF THE TRAILING JET, WHICH WAS DIRECTLY BEHIND US, AND A SECOND RA WAS RECOGNIZED BY THE TCASII. AT THIS POINT IN TIME, WE HAD TWO TARGETS -- ONE AT OUR 10 O'CLOCK POS AT FL245 AND THE JET AT OUR 6 O'CLOCK POS AT FL240 -- BOTH ACFT WERE WITHIN A RANGE OF 2 MI AS DEPICTED ON OUR MFD 1/2. IT IS ALSO NOTEWORTHY TO ADD, AS WE DSNDED INTO THE FLT PATH OF THE JET, AND THE SECOND RA WAS TRIGGERED, THE TCASII RA SEEMED TO GET 'CONFUSED' WITH ONE RA TARGET BEING HIGHER AND ONE RA TARGET BEING LOWER. THE SYS INITIALLY COMMANDED TO 'DSND' AND WITHIN A FEW SECONDS LATER COMMANDED A 'CLB' PER THE RA. AS WE WERE DSNDING PER THE RA, I COMMANDED FO TO STOP THE DSCNT OF OUR ACFT AT FL240 BECAUSE I COULD SEE OUR ACFT WAS ENCROACHING INTO THE SAME ALT AS THE JET. AS WE LEVELED THE ACFT AT FL240, I NOTICED THE SUBJECT JET HAD DSNDED TO FL235 AS DEPICTED ON MY MFD 1. AT SOME TIME, ATC ACKNOWLEDGED THE RECEIPT OF OUR DEV IN ALT AND VECTORED THE JET AWAY FROM OUR FLT PATH. SECONDS LATER, THE RA OF THE 10 O'CLOCK POS TFC HAD DISAPPEARED FROM OUR MFD 1/2. I VISUALLY SCANNED THE AREA FOR ANY THREAT AND THEN COMMANDED FO TO CLB BACK UP TO FL250 (OUR FILED ALT) TO ALLOW BETTER SEPARATION OF OUR ACFT FROM THE JET. ONCE AGAIN, AS WE BEGAN TO CLB THROUGH FL245, THE RA TFC REAPPEARED ON OUR MFD 1/2 AND AN IMMEDIATE RA WAS COMMANDED BY THE TCASII TO 'DSND, DSND' WHICH WE FOLLOWED TO AN ALT OF FL240. NO TARGET AT OUR 2 O'CLOCK WAS VISUALLY FOUND. ATC THEN INQUIRED ABOUT OUR DEV AND WE WERE CLRED BACK TO OUR ORIGINAL ALT. AS FLT LANDED IN PHX, GND CTL INFORMED US THAT ATC CTR WANTED TO TALK TO US AND RELAYED THE PHONE NUMBER. I WAS TO ASK FOR MR X. UPON ARR AT THE GATE, AND AS THE PAX WERE DEPLANING, I THEN CALLED MR X AND EXPLAINED IN DETAIL WHAT HAD JUST HAPPENED. MR X UNDERSTOOD THAT WE OBSERVED AN RA AND WE PERFORMED THE NECESSARY MANEUVER TO ELIMINATE THE CONFLICT, BUT MR X WAS CONCERNED ABOUT OUR ACTIONS BECAUSE OUR FLT PATH CAUSED A CONFLICT WITH THE TRAILING JET. MR X SEEMED HIGHLY AGITATED AND INFORMED ME 'AT NO TIME WAS THERE ANY AIR TFC AT FL245 AND AT NO TIME WAS THERE ANY AIR TFC IN CONFLICT TO OUR ACFT AS WE WERE CLBING TO FL250.' I ASSURED MR X THAT I'M QUITE SURE THAT 'HE' OBSERVED NO POTENTIAL TRAFFIC CONFLICT AS WE WERE CLBING TO OUR ASSIGNED FLT LEVEL OF FL250. NEVERTHELESS, I EXPLAINED TO MR X THAT HIS STATEMENT WAS IRRELEVANT BECAUSE OUR TCASII COMMANDED AN RA IN WHICH I EXPLAINED TO HIM WAS MANDATORY FOR OUR CREW TO COMPLY. THE CONFLICT THAT WE CAUSED IN REGARDS TO THE JET, IN MYOPINION, WAS CIRCUMSTANCE. IT IS ALSO IN MY OPINION THAT THE JET WAS ALLOWED TO BE 'TOO CLOSE' IN TRAIL OF OUR ACFT DURING OUR CLB. MR X STRONGLY SUGGESTED TO HAVE OUR TCASII SYS INSPECTED BECAUSE OF THE OBVIOUS ERRONEOUS TCASII RA. I AGREED. MR X THEN RELAYED TO ME THAT IT WAS NO FAULT OF OUR CREW AND HE WAS GOING TO DOCUMENT THE INCIDENT AS A 'TCASII INCIDENT.' AFTER I GOT OFF THE PHONE WITH MR X I THEN CALLED THE MAINT OPS DIRECTOR, AND RELAYED TO HIM THE SEQUENCE OF EVENTS. I ADVISED HIM OF THE ERRONEOUS INDICATION THAT THE TCASII PRODUCED AND THE POTENTIAL DISASTROUS OUTCOME THAT WAS AVOIDED IN REGARDS TO THE NEAR MISS OF THE JET. MR X INFORMED ME THAT OUR ACFT AT ONE POINT, CAME WITHIN 1 1/4 MI AND WITHIN 700 FT OF THE JET. SUPPLEMENTAL INFO FROM ACN 585823: THE FIRST AND THIRD RA'S WERE FOR AN ACFT SHOWING ON OUR TCASII DISPLAYS AT OUR 10 O'CLOCK POS AND ABOUT 10 MI. UPON TALKING WITH ATC, BOTH AFTER THE INCIDENT AND LATER BY PHONE ON THE GND, WE LEARNED THAT THERE WAS NO ACFT IN THAT AREA AT THE TIME. THIS IS WHY THE CTLR SEEMED IN DISBELIEF THAT WE WERE DSNDING PER THE RA.

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.