Crew was distraction and descended through assigned altitude.

Attributes
ACN	429910
Time
Date	199903
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : dxo.vor
State Reference	MI
Altitude	msl bound lower : 11400 msl bound upper : 12000
Environment
Flight Conditions	VMC VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : d10.tracon
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	fss specialist : 1 flight time last 90 days : 180 flight time total : 16000 flight time type : 300
ASRS Report	429910
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : commercial
Events
Anomaly	altitude deviation : overshoot non adherence : clearance non adherence : published procedure
Independent Detector	other controllera
Resolutory Action	controller : issued alert flight crew : returned to original clearance none taken : detected after the fact
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

First officer flying. Given clearance to cross fix at 12000 ft. Set in altitude selector with required call and confirmed by first officer. I believe that I missed the '1000 ft to go' call and was looking down to my left getting my charts set up for the approach when the controller asked us to 'check our altitude.' I looked up to see us at 11400 ft. We returned to 12000 ft. I believe the following contributed to this occurrence: 1) complacency. It was the last leg of an all day trip and I was feeling comfortable with the first officer's abilities. Even though it was his third month on the job. 2) distraction. Made a poor decision to become involved with charts during a critical period. 3) procedural error. I believe I missed the '1000 ft to go' call and somehow at the same time the first officer became convinced that he was supposed to descend to 11000 ft.

Original NASA ASRS Text

Title: CREW WAS DISTR AND DSNDED THROUGH ASSIGNED ALT.

Narrative: FO FLYING. GIVEN CLRNC TO CROSS FIX AT 12000 FT. SET IN ALT SELECTOR WITH REQUIRED CALL AND CONFIRMED BY FO. I BELIEVE THAT I MISSED THE '1000 FT TO GO' CALL AND WAS LOOKING DOWN TO MY L GETTING MY CHARTS SET UP FOR THE APCH WHEN THE CTLR ASKED US TO 'CHK OUR ALT.' I LOOKED UP TO SEE US AT 11400 FT. WE RETURNED TO 12000 FT. I BELIEVE THE FOLLOWING CONTRIBUTED TO THIS OCCURRENCE: 1) COMPLACENCY. IT WAS THE LAST LEG OF AN ALL DAY TRIP AND I WAS FEELING COMFORTABLE WITH THE FO'S ABILITIES. EVEN THOUGH IT WAS HIS THIRD MONTH ON THE JOB. 2) DISTR. MADE A POOR DECISION TO BECOME INVOLVED WITH CHARTS DURING A CRITICAL PERIOD. 3) PROCEDURAL ERROR. I BELIEVE I MISSED THE '1000 FT TO GO' CALL AND SOMEHOW AT THE SAME TIME THE FO BECAME CONVINCED THAT HE WAS SUPPOSED TO DSND TO 11000 FT.

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.