Narrative:

We were descending in holding to FL220, first officer was the PF. The captain (PNF) was clearing a sinus block. I was cleared lower, I thought it was to FL190. The PNF did not hear the clearance, but saw me set FL190 in the altitude reminder and he read back the clearance to FL190. While turning to the outbound holding leg, I noticed another target 8 mi away and at our altitude on the TCASII (FL190). The PNF immediately called ATC to ask about the target. I acquired the target visually by the time ATC responded. There was no conflict, as the other aircraft did not get closer than 5 mi and was on the inbound leg. ATC then responded that we were only cleared to FL200 and turned us inbound behind the traffic without incident. At this time I am unsure as to whether we were cleared to FL190 or FL200. I may have set FL200 in the altitude reminder and it bumped to FL190 (if it is half way between settings, it can read what you wanted set and a moment later, click to the next setting), or else we were cleared to FL190 and I set it properly. Regardless of what the clearance was, the TCASII display brought the problem to our attention first. The TCASII has proven its value once again. There were no warnings or RA's given by the TCASII as there was not a conflict. A contributing factor was an ear block developed by the captain during this leg. It made it difficult for him to hear and repeatedly distracted him as he tried to clear it. The problem was significant enough for the captain to remove himself from the rest of the trip and to report in sick.

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Original NASA ASRS Text

Title: MLG FLC HAS SOME CONFUSION REF ALT CLRNC. ALTDEV IN HOLDING.

Narrative: WE WERE DSNDING IN HOLDING TO FL220, FO WAS THE PF. THE CAPT (PNF) WAS CLRING A SINUS BLOCK. I WAS CLRED LOWER, I THOUGHT IT WAS TO FL190. THE PNF DID NOT HEAR THE CLRNC, BUT SAW ME SET FL190 IN THE ALT REMINDER AND HE READ BACK THE CLRNC TO FL190. WHILE TURNING TO THE OUTBOUND HOLDING LEG, I NOTICED ANOTHER TARGET 8 MI AWAY AND AT OUR ALT ON THE TCASII (FL190). THE PNF IMMEDIATELY CALLED ATC TO ASK ABOUT THE TARGET. I ACQUIRED THE TARGET VISUALLY BY THE TIME ATC RESPONDED. THERE WAS NO CONFLICT, AS THE OTHER ACFT DID NOT GET CLOSER THAN 5 MI AND WAS ON THE INBOUND LEG. ATC THEN RESPONDED THAT WE WERE ONLY CLRED TO FL200 AND TURNED US INBOUND BEHIND THE TFC WITHOUT INCIDENT. AT THIS TIME I AM UNSURE AS TO WHETHER WE WERE CLRED TO FL190 OR FL200. I MAY HAVE SET FL200 IN THE ALT REMINDER AND IT BUMPED TO FL190 (IF IT IS HALF WAY BTWN SETTINGS, IT CAN READ WHAT YOU WANTED SET AND A MOMENT LATER, CLICK TO THE NEXT SETTING), OR ELSE WE WERE CLRED TO FL190 AND I SET IT PROPERLY. REGARDLESS OF WHAT THE CLRNC WAS, THE TCASII DISPLAY BROUGHT THE PROB TO OUR ATTN FIRST. THE TCASII HAS PROVEN ITS VALUE ONCE AGAIN. THERE WERE NO WARNINGS OR RA'S GIVEN BY THE TCASII AS THERE WAS NOT A CONFLICT. A CONTRIBUTING FACTOR WAS AN EAR BLOCK DEVELOPED BY THE CAPT DURING THIS LEG. IT MADE IT DIFFICULT FOR HIM TO HEAR AND REPEATEDLY DISTRACTED HIM AS HE TRIED TO CLR IT. THE PROB WAS SIGNIFICANT ENOUGH FOR THE CAPT TO REMOVE HIMSELF FROM THE REST OF THE TRIP AND TO RPT IN SICK.

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.