Narrative:

I was instructing on an instrument training flight. We were performing VOR intercepts and holding patterns. I was monitoring albuquerque center (128.45), but had not contacted them. At the time of the incident we were holding over oates intersection at 12000'. Our transponder was on and we thought the encoder was operating normally because only a little while before the incident we were given as traffic at 12000' to an air carrier flight southbound out flagstaff (an assumption based on our position and what we heard center telling the air carrier flight). We never saw the traffic reporting the near miss. We heard him report the near miss. At that time we became increasingly alert, even though we at this time did not know that we were the other aircraft involved. Only after we heard center giving the location of the occurrence did we suspect that we were indeed the other aircraft involved. We never did see the conflicting aircraft. The other pilot was told by center that he did indeed have us on the scope, but we were not encoding so he didn't give us as traffic. He then told the other pilot that he was now receiving our altitude encoder, and we were at 12000'. Why were we not given as traffic if we were converging? It seems that we were ignored because our altitude was not encoding. I would think that equipment failures should be expected and due caution exercised. I should have contacted center and told them what I was doing. I was making the same assumption that my encoder was operating and that he had us in contact. Upon returning to my home base (flagstaff) I was asked to call center. I contacted them and related essentially this same information to them.

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Original NASA ASRS Text

Title: FLT CREW OF ACR CLIMBING OUT OF FLG REPORTS CONFLICT WITH REPORTER'S ACFT WHEN REPORTER WAS GIVING INSTRUMENT FLT INSTRUCTION AT 12000'. CTLR CLAIMS THAT REPORTER'S MODE C WAS INTERMITTENT.

Narrative: I WAS INSTRUCTING ON AN INSTRUMENT TRAINING FLT. WE WERE PERFORMING VOR INTERCEPTS AND HOLDING PATTERNS. I WAS MONITORING ALBUQUERQUE CENTER (128.45), BUT HAD NOT CONTACTED THEM. AT THE TIME OF THE INCIDENT WE WERE HOLDING OVER OATES INTXN AT 12000'. OUR XPONDER WAS ON AND WE THOUGHT THE ENCODER WAS OPERATING NORMALLY BECAUSE ONLY A LITTLE WHILE BEFORE THE INCIDENT WE WERE GIVEN AS TFC AT 12000' TO AN ACR FLT SBND OUT FLAGSTAFF (AN ASSUMPTION BASED ON OUR POSITION AND WHAT WE HEARD CENTER TELLING THE ACR FLT). WE NEVER SAW THE TFC REPORTING THE NEAR MISS. WE HEARD HIM REPORT THE NEAR MISS. AT THAT TIME WE BECAME INCREASINGLY ALERT, EVEN THOUGH WE AT THIS TIME DID NOT KNOW THAT WE WERE THE OTHER ACFT INVOLVED. ONLY AFTER WE HEARD CENTER GIVING THE LOCATION OF THE OCCURRENCE DID WE SUSPECT THAT WE WERE INDEED THE OTHER ACFT INVOLVED. WE NEVER DID SEE THE CONFLICTING ACFT. THE OTHER PLT WAS TOLD BY CENTER THAT HE DID INDEED HAVE US ON THE SCOPE, BUT WE WERE NOT ENCODING SO HE DIDN'T GIVE US AS TFC. HE THEN TOLD THE OTHER PLT THAT HE WAS NOW RECEIVING OUR ALT ENCODER, AND WE WERE AT 12000'. WHY WERE WE NOT GIVEN AS TFC IF WE WERE CONVERGING? IT SEEMS THAT WE WERE IGNORED BECAUSE OUR ALT WAS NOT ENCODING. I WOULD THINK THAT EQUIPMENT FAILURES SHOULD BE EXPECTED AND DUE CAUTION EXERCISED. I SHOULD HAVE CONTACTED CENTER AND TOLD THEM WHAT I WAS DOING. I WAS MAKING THE SAME ASSUMPTION THAT MY ENCODER WAS OPERATING AND THAT HE HAD US IN CONTACT. UPON RETURNING TO MY HOME BASE (FLAGSTAFF) I WAS ASKED TO CALL CENTER. I CONTACTED THEM AND RELATED ESSENTIALLY THIS SAME INFO TO THEM.

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.