Narrative:

On 11/X/91, I picked up an aircraft at dfw. It was the first leg of the last day on a 3 day trip. Going over the dispatch release I noted a MEL item TCASII inoperative. Preflight, takeoff, and cruise were uneventful. Upon descent out of 35000, at 23800 our TCASII (located on our ivsi) turned red and stated climb. We climbed back over FL340 and notified ATC. They stated no traffic. We continued our descent. It was later remembered the TCASII was inoperative. It is the fos duty to turn on the transponder before takeoff and he positioned it to TCASII. We had no yellow sticker on the transponder stating it was inoperative. The TCASII fail message did not occur. The transponder TCASII circuit breaker had not been out or collared.

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Original NASA ASRS Text

Title: ACR MLG ALT DEV REVERSED DSCNT IN RESPONSE TO AN INOP TCASII RA.

Narrative: ON 11/X/91, I PICKED UP AN ACFT AT DFW. IT WAS THE FIRST LEG OF THE LAST DAY ON A 3 DAY TRIP. GOING OVER THE DISPATCH RELEASE I NOTED A MEL ITEM TCASII INOP. PREFLT, TKOF, AND CRUISE WERE UNEVENTFUL. UPON DSCNT OUT OF 35000, AT 23800 OUR TCASII (LOCATED ON OUR IVSI) TURNED RED AND STATED CLB. WE CLBED BACK OVER FL340 AND NOTIFIED ATC. THEY STATED NO TFC. WE CONTINUED OUR DSCNT. IT WAS LATER REMEMBERED THE TCASII WAS INOP. IT IS THE FOS DUTY TO TURN ON THE TRANSPONDER BEFORE TKOF AND HE POSITIONED IT TO TCASII. WE HAD NO YELLOW STICKER ON THE TRANSPONDER STATING IT WAS INOP. THE TCASII FAIL MESSAGE DID NOT OCCUR. THE TRANSPONDER TCASII CB HAD NOT BEEN OUT OR COLLARED.

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.