Narrative:

During descent from FL340 to FL310; the autoplt initiated the leveloff with the vertical speed reducing to approximately 100 FPM at FL311 (100 ft above the selected altitude). The aircraft then continued to descend approximately 300 to 400 ft; the autoplt was disconnected and we corrected back to altitude (FL310). Center directed a descent to a lower altitude at that time and noted no problems with our altitude. During the leveloff (within 100 ft of the selected altitude); we received multiple engine #2 fire detect warnings (ECAM warnings and chime); which momentarily distracted us as the aircraft was completing the leveloff. The fire detect system was turned off; and a write-up was entered into the log book in accordance with aircraft procedures. Callback conversation with reporter revealed the following information: reporter is a flight standards pilot and check airman on this aircraft. He stated that all conditions for an FMC altitude capture were met. The FMA indications at the time of the excursion were speed/altitude indicating that both speed and altitude were being commanded as they approached the assigned altitude; but the aircraft continued another 300 to 400 ft before the crew caught the deviation. They were also distracted by the intermittent fire warning.

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Original NASA ASRS Text

Title: AN A300 IN THE PROFILE DSCNT MODE INDICATED PROPER FMA ALT CAPTURE ANNUNCIATIONS; BUT FAILED TO CAPTURE THE PROGRAMMED ALT.

Narrative: DURING DSCNT FROM FL340 TO FL310; THE AUTOPLT INITIATED THE LEVELOFF WITH THE VERT SPD REDUCING TO APPROX 100 FPM AT FL311 (100 FT ABOVE THE SELECTED ALT). THE ACFT THEN CONTINUED TO DSND APPROX 300 TO 400 FT; THE AUTOPLT WAS DISCONNECTED AND WE CORRECTED BACK TO ALT (FL310). CTR DIRECTED A DSCNT TO A LOWER ALT AT THAT TIME AND NOTED NO PROBS WITH OUR ALT. DURING THE LEVELOFF (WITHIN 100 FT OF THE SELECTED ALT); WE RECEIVED MULTIPLE ENGINE #2 FIRE DETECT WARNINGS (ECAM WARNINGS AND CHIME); WHICH MOMENTARILY DISTRACTED US AS THE ACFT WAS COMPLETING THE LEVELOFF. THE FIRE DETECT SYSTEM WAS TURNED OFF; AND A WRITE-UP WAS ENTERED INTO THE LOG BOOK IN ACCORDANCE WITH ACFT PROCS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR IS A FLT STANDARDS PLT AND CHK AIRMAN ON THIS ACFT. HE STATED THAT ALL CONDITIONS FOR AN FMC ALT CAPTURE WERE MET. THE FMA INDICATIONS AT THE TIME OF THE EXCURSION WERE SPEED/ALT INDICATING THAT BOTH SPEED AND ALT WERE BEING COMMANDED AS THEY APCHED THE ASSIGNED ALT; BUT THE ACFT CONTINUED ANOTHER 300 TO 400 FT BEFORE THE CREW CAUGHT THE DEVIATION. THEY WERE ALSO DISTRACTED BY THE INTERMITTENT FIRE WARNING.

Data retrieved from NASA's ASRS site as of January 2009 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.