Narrative:

Lax approach gave us a vector from the standard sadde 6 arrival to fly directly over the airport to the south side for a visual to the south (cargo) runway complex. While descending to 10000 ft the copilot (PF) descended to 9600 ft before we caught his deviation. As we were heavy (620000 pounds) he was unable to get the aircraft back up to 10000 ft quickly, so the controller seeing our situation cleared us to a lower altitude. The controller never said anything to us, but it was obvious he 'bailed' us out of our predicament. Having just been given the south runways we were all getting the other approach plates out to brief and back us up, fine except the first officer should have been flying the plane. The first officer was fairly new to the right seat (3 months) and had been an engineer (like myself) for 11 yrs. It was his first co-pilot check-out and he had never landed at lax. In 14 yrs of flying at 7 airlines I have witnessed more altdevs in 2 1/2 yrs as an flight engineer on this airplane. I believe a good reason for this is too many guys sitting in the 'back-seat' (so) for too long and getting very rusty piloting skills as a result. (Make a mental note to myself.) the captain had also just come back from a knee injury after being off work for 3 months. It was clear and we were early arriving so it was not very busy traffic wise, so no conflict resulted. It was also a short (4 1/2 hour) day flight from anc-lax so fatigue should not have been a factor. I chalk this up to lack of proficiency.

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Original NASA ASRS Text

Title: A B747-200 FREIGHTER OVERSHOOTS ITS ASSIGNED ALT IN DSCNT WHEN THE CREW BECOMES DISTRACTED WITH OBTAINING APCH PLATES FOR A RWY CHANGE AT LAX, CA.

Narrative: LAX APCH GAVE US A VECTOR FROM THE STANDARD SADDE 6 ARR TO FLY DIRECTLY OVER THE ARPT TO THE S SIDE FOR A VISUAL TO THE S (CARGO) RWY COMPLEX. WHILE DSNDING TO 10000 FT THE COPLT (PF) DSNDED TO 9600 FT BEFORE WE CAUGHT HIS DEV. AS WE WERE HVY (620000 LBS) HE WAS UNABLE TO GET THE ACFT BACK UP TO 10000 FT QUICKLY, SO THE CTLR SEEING OUR SIT CLRED US TO A LOWER ALT. THE CTLR NEVER SAID ANYTHING TO US, BUT IT WAS OBVIOUS HE 'BAILED' US OUT OF OUR PREDICAMENT. HAVING JUST BEEN GIVEN THE S RWYS WE WERE ALL GETTING THE OTHER APCH PLATES OUT TO BRIEF AND BACK US UP, FINE EXCEPT THE FO SHOULD HAVE BEEN FLYING THE PLANE. THE FO WAS FAIRLY NEW TO THE R SEAT (3 MONTHS) AND HAD BEEN AN ENGINEER (LIKE MYSELF) FOR 11 YRS. IT WAS HIS FIRST CO-PLT CHK-OUT AND HE HAD NEVER LANDED AT LAX. IN 14 YRS OF FLYING AT 7 AIRLINES I HAVE WITNESSED MORE ALTDEVS IN 2 1/2 YRS AS AN FE ON THIS AIRPLANE. I BELIEVE A GOOD REASON FOR THIS IS TOO MANY GUYS SITTING IN THE 'BACK-SEAT' (SO) FOR TOO LONG AND GETTING VERY RUSTY PILOTING SKILLS AS A RESULT. (MAKE A MENTAL NOTE TO MYSELF.) THE CAPT HAD ALSO JUST COME BACK FROM A KNEE INJURY AFTER BEING OFF WORK FOR 3 MONTHS. IT WAS CLR AND WE WERE EARLY ARRIVING SO IT WAS NOT VERY BUSY TFC WISE, SO NO CONFLICT RESULTED. IT WAS ALSO A SHORT (4 1/2 HR) DAY FLT FROM ANC-LAX SO FATIGUE SHOULD NOT HAVE BEEN A FACTOR. I CHALK THIS UP TO LACK OF PROFICIENCY.

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.