Narrative:

While listening to the ATIS in descent I set 29.33 into backup bar altimeter. -29.92 remained on the primary altimeter. It was bad and cockpit workload was very high (see contributing factors). Also, in period of 5 mins we had 3 different runway changes from approach control ('expect ILS to runway...'). When the approach descent checklist was read, I apparently southeast both of my altimeters to 29.92 rather than 29.33. I cannot explain why. The copilot did not visually or orally confirm my altimeter setting as required by SOP. As I descended through 2500' MSL with the erroneous setting, the copilot yelled, 'altitude.' I disconnected the autoplt, stopped the descent and climbed back to 2500' using the foj altimeter as reference. At about the same time, approach reinstructed us to maintain 2500'. Estimate altitude deviation at 200-230' low before corrective action. Subsequent approach and landing was normal. In the medium large transport cockpit, at night with lighting turned down for approach and landing, it is very difficult, if not impossible, for the PNF (reading the approach checklist) to visually confirm the correct altimeter setting in the PF's altimeter. The #south are too small and the distance too great. For this reason, I believe all altimeter settings should be verbally confirmed by each pilot, both on descent and in climb out after passing FL180. When arriving from the north over smo VOR, lax approach control has the bad habit of almost routinely changing runways on you after passing smo (often several times). In IFR weight, this adds a high workload in a 2-M glass cockpit. Not only does the ILS receiver have to be retuned and and idented, but numerous CDU inputs must be made on the FMC if the approach fixes and extended centerline are to be presented on the map mode. This is desirable if you are IFR. As illustrated above, it is not difficult to overload a 2-M glass cockpit crew on approach. Hopefully, air carrier's will address this situation and change prescribed standard operating procedures where necessary. I recently rode as a cockpit passenger in one of our non glass medium large transport's. I was amazed at the simplicity, reduced workload and more relaxed atmosphere as compared to the glass medium large transport. I believe there is a message here. Does technology really reduce workload and make it safer??

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Original NASA ASRS Text

Title: ALT DEVIATION ALT OVERSHOT ON DESCENT DUE TO IMPROPERLY SET ALTIMETER.

Narrative: WHILE LISTENING TO THE ATIS IN DSNT I SET 29.33 INTO BACKUP BAR ALTIMETER. -29.92 REMAINED ON THE PRIMARY ALTIMETER. IT WAS BAD AND COCKPIT WORKLOAD WAS VERY HIGH (SEE CONTRIBUTING FACTORS). ALSO, IN PERIOD OF 5 MINS WE HAD 3 DIFFERENT RWY CHANGES FROM APCH CTL ('EXPECT ILS TO RWY...'). WHEN THE APCH DSNT CHKLIST WAS READ, I APPARENTLY SE BOTH OF MY ALTIMETERS TO 29.92 RATHER THAN 29.33. I CANNOT EXPLAIN WHY. THE COPLT DID NOT VISUALLY OR ORALLY CONFIRM MY ALTIMETER SETTING AS REQUIRED BY SOP. AS I DSNDED THROUGH 2500' MSL WITH THE ERRONEOUS SETTING, THE COPLT YELLED, 'ALT.' I DISCONNECTED THE AUTOPLT, STOPPED THE DSNT AND CLBED BACK TO 2500' USING THE FOJ ALTIMETER AS REF. AT ABOUT THE SAME TIME, APCH REINSTRUCTED US TO MAINTAIN 2500'. ESTIMATE ALT DEVIATION AT 200-230' LOW BEFORE CORRECTIVE ACTION. SUBSEQUENT APCH AND LNDG WAS NORMAL. IN THE MLG COCKPIT, AT NIGHT WITH LIGHTING TURNED DOWN FOR APCH AND LNDG, IT IS VERY DIFFICULT, IF NOT IMPOSSIBLE, FOR THE PNF (READING THE APCH CHKLIST) TO VISUALLY CONFIRM THE CORRECT ALTIMETER SETTING IN THE PF'S ALTIMETER. THE #S ARE TOO SMALL AND THE DISTANCE TOO GREAT. FOR THIS REASON, I BELIEVE ALL ALTIMETER SETTINGS SHOULD BE VERBALLY CONFIRMED BY EACH PLT, BOTH ON DSNT AND IN CLBOUT AFTER PASSING FL180. WHEN ARRIVING FROM THE N OVER SMO VOR, LAX APCH CTL HAS THE BAD HABIT OF ALMOST ROUTINELY CHANGING RWYS ON YOU AFTER PASSING SMO (OFTEN SEVERAL TIMES). IN IFR WT, THIS ADDS A HIGH WORKLOAD IN A 2-M GLASS COCKPIT. NOT ONLY DOES THE ILS RECEIVER HAVE TO BE RETUNED AND AND IDENTED, BUT NUMEROUS CDU INPUTS MUST BE MADE ON THE FMC IF THE APCH FIXES AND EXTENDED CENTERLINE ARE TO BE PRESENTED ON THE MAP MODE. THIS IS DESIRABLE IF YOU ARE IFR. AS ILLUSTRATED ABOVE, IT IS NOT DIFFICULT TO OVERLOAD A 2-M GLASS COCKPIT CREW ON APCH. HOPEFULLY, ACR'S WILL ADDRESS THIS SITUATION AND CHANGE PRESCRIBED STANDARD OPERATING PROCS WHERE NECESSARY. I RECENTLY RODE AS A COCKPIT PAX IN ONE OF OUR NON GLASS MLG'S. I WAS AMAZED AT THE SIMPLICITY, REDUCED WORKLOAD AND MORE RELAXED ATMOSPHERE AS COMPARED TO THE GLASS MLG. I BELIEVE THERE IS A MESSAGE HERE. DOES TECHNOLOGY REALLY REDUCE WORKLOAD AND MAKE IT SAFER??

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.