Narrative:

Flight at cruise altitude of FL310. ATC gave clearance to FL290. I, PNF, read back clearance to FL290. Because I was manipulating my map and was getting my fom manual out of my flight case, PF set in new altitude and also verbally stated new altitude cleared to. The altitude set in was 19000 ft and the verbal acknowledgement was covered up by another radio transmission. We got a 'traffic' TCASII alert at 28500 ft and PF started right backup to 29000 ft. ATC asked if we were level at FL290. I said we are going to FL290 and asked for confirmation. TA was seen on screen at 1:30 O'clock position and FL280. I verified visually at about 2 O'clock position and watched aircraft go from 2 O'clock to 4:30 O'clock position below us. No avoidance was necessary. SOP calls for PNF to read back clearance, set new altitude in window, and point to altitude indicator until PF verifies. My hands were busy and PF set in new altitude. I did not clearly hear his altitude stated. We were not able to do SOP. I should have verified again. Supplemental information from acn 234800: the first officer, PNF, answered on the radio 'cleared to FL290' (with his right hand). At the same time my voice said FL190 in the cockpit. I did not hear the first officer say FL290 and he did not hear me state FL190. I set FL190 in the altitude alert box. I failed to coordinate with him on the altitude and he failed to see I had set something different than what he repeated over the radio. Our internal cockpit communications and failure to confirm the clearance to FL290 resulted in an altitude deviation. Our internal SOP procedures have been discussed and reviewed and corrected.

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Original NASA ASRS Text

Title: AN ACR MLG CREW CLBED IN RESPONSE TO A TCASII COMMAND. THE CREW HAD OVERSHOT ITS ASSIGNED ALT.

Narrative: FLT AT CRUISE ALT OF FL310. ATC GAVE CLRNC TO FL290. I, PNF, READ BACK CLRNC TO FL290. BECAUSE I WAS MANIPULATING MY MAP AND WAS GETTING MY FOM MANUAL OUT OF MY FLT CASE, PF SET IN NEW ALT AND ALSO VERBALLY STATED NEW ALT CLRED TO. THE ALT SET IN WAS 19000 FT AND THE VERBAL ACKNOWLEDGEMENT WAS COVERED UP BY ANOTHER RADIO XMISSION. WE GOT A 'TFC' TCASII ALERT AT 28500 FT AND PF STARTED R BACKUP TO 29000 FT. ATC ASKED IF WE WERE LEVEL AT FL290. I SAID WE ARE GOING TO FL290 AND ASKED FOR CONFIRMATION. TA WAS SEEN ON SCREEN AT 1:30 O'CLOCK POS AND FL280. I VERIFIED VISUALLY AT ABOUT 2 O'CLOCK POS AND WATCHED ACFT GO FROM 2 O'CLOCK TO 4:30 O'CLOCK POS BELOW US. NO AVOIDANCE WAS NECESSARY. SOP CALLS FOR PNF TO READ BACK CLRNC, SET NEW ALT IN WINDOW, AND POINT TO ALT INDICATOR UNTIL PF VERIFIES. MY HANDS WERE BUSY AND PF SET IN NEW ALT. I DID NOT CLRLY HEAR HIS ALT STATED. WE WERE NOT ABLE TO DO SOP. I SHOULD HAVE VERIFIED AGAIN. SUPPLEMENTAL INFO FROM ACN 234800: THE FO, PNF, ANSWERED ON THE RADIO 'CLRED TO FL290' (WITH HIS R HAND). AT THE SAME TIME MY VOICE SAID FL190 IN THE COCKPIT. I DID NOT HEAR THE FO SAY FL290 AND HE DID NOT HEAR ME STATE FL190. I SET FL190 IN THE ALT ALERT BOX. I FAILED TO COORDINATE WITH HIM ON THE ALT AND HE FAILED TO SEE I HAD SET SOMETHING DIFFERENT THAN WHAT HE REPEATED OVER THE RADIO. OUR INTERNAL COCKPIT COMS AND FAILURE TO CONFIRM THE CLRNC TO FL290 RESULTED IN AN ALTDEV. OUR INTERNAL SOP PROCS HAVE BEEN DISCUSSED AND REVIEWED AND CORRECTED.

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.