Narrative:

During climb out from hnl en route to nrt we experienced mechanical problems with 1 leading edge flap. During our troubleshooting and assessment of the situation, ATC instructed us to descend to 15000 ft. While deeply involved with the flight manual irregular procedure and with company communications, I felt the aircraft g-loading increasing abnormally. I looked up and saw us in a climbing turn and altitude of about 14600 ft. I checked the altitude select window, saw 15000 ft, and assumed that the PF had inadvertently descended through the assigned altitude and was correcting aggressively. We leveled off at 15000 ft and continued our irregular operation. At the time of the incident, the cockpit was extremely busy and noisy, partially due to the distraction caused by a flight attendant in the cockpit reporting on his perception of relevant sights/sounds associated with the mechanical problem. Also, the captain was the PF and was task-saturated while trying to listen to all inputs from all sources. I do not know why the first officer did not catch the altitude deviation, but I suspect it was because he too was distracted by all the cockpit activity. Perhaps better division of cockpit duties (e.g., having the first officer fly the aircraft while the captain managed the overall situation) would have lessened the chances of such an incident. Supplemental information from acn 229826: we were returning to hnl because of a leading edge device malfunction. Center cleared us to maintain 15000 ft prior to fuel dump. Light to moderate turbulence, rain and speed restrictions due to slat malfunction, as well as preparing for fuel dump.

Related reports:

Google
 

Original NASA ASRS Text

Title: A WDB ACR ACFT OVERSHOT ITS ALT ON DSCNT WHILE TRYING TO SOLVE A MECHANICAL PROB PRIOR TO DUMPING FUEL.

Narrative: DURING CLBOUT FROM HNL ENRTE TO NRT WE EXPERIENCED MECHANICAL PROBS WITH 1 LEADING EDGE FLAP. DURING OUR TROUBLESHOOTING AND ASSESSMENT OF THE SIT, ATC INSTRUCTED US TO DSND TO 15000 FT. WHILE DEEPLY INVOLVED WITH THE FLT MANUAL IRREGULAR PROC AND WITH COMPANY COMS, I FELT THE ACFT G-LOADING INCREASING ABNORMALLY. I LOOKED UP AND SAW US IN A CLBING TURN AND ALT OF ABOUT 14600 FT. I CHKED THE ALT SELECT WINDOW, SAW 15000 FT, AND ASSUMED THAT THE PF HAD INADVERTENTLY DSNDED THROUGH THE ASSIGNED ALT AND WAS CORRECTING AGGRESSIVELY. WE LEVELED OFF AT 15000 FT AND CONTINUED OUR IRREGULAR OP. AT THE TIME OF THE INCIDENT, THE COCKPIT WAS EXTREMELY BUSY AND NOISY, PARTIALLY DUE TO THE DISTR CAUSED BY A FLT ATTENDANT IN THE COCKPIT RPTING ON HIS PERCEPTION OF RELEVANT SIGHTS/SOUNDS ASSOCIATED WITH THE MECHANICAL PROB. ALSO, THE CAPT WAS THE PF AND WAS TASK-SATURATED WHILE TRYING TO LISTEN TO ALL INPUTS FROM ALL SOURCES. I DO NOT KNOW WHY THE FO DID NOT CATCH THE ALTDEV, BUT I SUSPECT IT WAS BECAUSE HE TOO WAS DISTRACTED BY ALL THE COCKPIT ACTIVITY. PERHAPS BETTER DIVISION OF COCKPIT DUTIES (E.G., HAVING THE FO FLY THE ACFT WHILE THE CAPT MANAGED THE OVERALL SIT) WOULD HAVE LESSENED THE CHANCES OF SUCH AN INCIDENT. SUPPLEMENTAL INFO FROM ACN 229826: WE WERE RETURNING TO HNL BECAUSE OF A LEADING EDGE DEVICE MALFUNCTION. CTR CLRED US TO MAINTAIN 15000 FT PRIOR TO FUEL DUMP. LIGHT TO MODERATE TURB, RAIN AND SPD RESTRICTIONS DUE TO SLAT MALFUNCTION, AS WELL AS PREPARING FOR FUEL DUMP.

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.