Altitude deviation on approach. Pilot fatigue.

Attributes
ACN	305550
Time
Date	199505
Day	Sun
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : san
State Reference	CA
Altitude	msl bound lower : 6600 msl bound upper : 7000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : san
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 135
Flight Phase	descent : approach descent other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : atp
Experience	flight time last 90 days : 200 flight time total : 5000 flight time type : 2000
ASRS Report	305550
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	altitude deviation : overshoot non adherence : clearance
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

During descent into san we were assigned leveloff of 7000 ft MSL. The first officer set 7000 ft in the alerter and I acknowledged the alerter. I then made the company required 500 ft-to-go call. In spite of this, I descended through the assigned altitude by 400 ft. Possibly contributing was fatigue. I was flying at the time I had been going to sleep or already asleep for a couple of weeks.

Original NASA ASRS Text

Title: ALTDEV ON APCH. PLT FATIGUE.

Narrative: DURING DSCNT INTO SAN WE WERE ASSIGNED LEVELOFF OF 7000 FT MSL. THE FO SET 7000 FT IN THE ALERTER AND I ACKNOWLEDGED THE ALERTER. I THEN MADE THE COMPANY REQUIRED 500 FT-TO-GO CALL. IN SPITE OF THIS, I DSNDED THROUGH THE ASSIGNED ALT BY 400 FT. POSSIBLY CONTRIBUTING WAS FATIGUE. I WAS FLYING AT THE TIME I HAD BEEN GOING TO SLEEP OR ALREADY ASLEEP FOR A COUPLE OF WKS.

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.