A descending B737 overshot its assigned altitude when the PIC does not reset his altimeter to local ...

Attributes
ACN	406030
Time
Date	199806
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : lfv airport : bos
State Reference	MA
Altitude	msl bound lower : 11800 msl bound upper : 12000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : bos
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	descent other other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : cfi pilot : atp
Experience	flight time last 90 days : 200 flight time total : 7000 flight time type : 1000
ASRS Report	406030
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	altitude deviation : overshoot non adherence : clearance non adherence other other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : became reoriented flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

The 4TH amendment to our arrival clearance into boston was a clearance to the lfv VOR and then expect radar vectors. We were on a descent to 15000 ft as we approached the VOR and still had not received a vector for after the VOR. As we crossed the lfv VOR we requested a heading and approach control cleared us to the scupp intersection. As we intercepted the outbound radial to scupp, we were given a descent clearance to 12000 ft and holding instructions at scupp. We were also notified of a runway change and to now expect runway 22L instead of runway 27. As we approached scupp intersection the aircraft leveled off at 12000 ft (autoplt on). The first officer noticed the captain had not reset his altimeter to the local altimeter setting. The aircraft had leveled off approximately 200 ft low at 11800 ft. The aircraft was immediately climbed back to 12000 ft. Approach control made no comment about the discrepancy and the flight continued as planned. I believe the problem was caused by a combination of factors. The clearance changes, runway change, holding instructions, and also a new ATIS information all combined for a very busy cockpit environment. In this process a descent checklist was not completed and led to the faulty altimeter setting.

Original NASA ASRS Text

Title: A DSNDING B737 OVERSHOT ITS ASSIGNED ALT WHEN THE PIC DOES NOT RESET HIS ALTIMETER TO LCL QNH. CREW HAD NOT COMPLETED THEIR DSCNT CHKLIST ON ACCOUNT OF ATC BURDENS.

Narrative: THE 4TH AMENDMENT TO OUR ARR CLRNC INTO BOSTON WAS A CLRNC TO THE LFV VOR AND THEN EXPECT RADAR VECTORS. WE WERE ON A DSCNT TO 15000 FT AS WE APCHED THE VOR AND STILL HAD NOT RECEIVED A VECTOR FOR AFTER THE VOR. AS WE CROSSED THE LFV VOR WE REQUESTED A HEADING AND APCH CTL CLRED US TO THE SCUPP INTXN. AS WE INTERCEPTED THE OUTBOUND RADIAL TO SCUPP, WE WERE GIVEN A DSCNT CLRNC TO 12000 FT AND HOLDING INSTRUCTIONS AT SCUPP. WE WERE ALSO NOTIFIED OF A RWY CHANGE AND TO NOW EXPECT RWY 22L INSTEAD OF RWY 27. AS WE APCHED SCUPP INTXN THE ACFT LEVELED OFF AT 12000 FT (AUTOPLT ON). THE FO NOTICED THE CAPT HAD NOT RESET HIS ALTIMETER TO THE LCL ALTIMETER SETTING. THE ACFT HAD LEVELED OFF APPROX 200 FT LOW AT 11800 FT. THE ACFT WAS IMMEDIATELY CLBED BACK TO 12000 FT. APCH CTL MADE NO COMMENT ABOUT THE DISCREPANCY AND THE FLT CONTINUED AS PLANNED. I BELIEVE THE PROB WAS CAUSED BY A COMBINATION OF FACTORS. THE CLRNC CHANGES, RWY CHANGE, HOLDING INSTRUCTIONS, AND ALSO A NEW ATIS INFO ALL COMBINED FOR A VERY BUSY COCKPIT ENVIRONMENT. IN THIS PROCESS A DSCNT CHKLIST WAS NOT COMPLETED AND LED TO THE FAULTY ALTIMETER SETTING.

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.

A descending B737 overshot its assigned altitude when the PIC does not reset his altimeter to local qnh. Crew had not completed their descent checklist on account of ATC burdens.